Since production on Season 9 got underway the 'Two and a Half Men' set has been shrouded in secrecy. Promos have teased that all will be revealed in the premiere episode.

Last night, however, we got a sneak peek at the new Sheen-less 'Men' courtesy of David Letterman and 'Late Show.' And there was not a bowling shirt in sight.

Series stars Ashton Kutcher, Jon Cryer and Angus T. Jones presented last night's Top Ten list on 'Late Show,' which, fittingly enough, was The Top Ten Reasons to Watch the New Season of 'Two and a Half Men.'

Watch highlights from the Top Ten after the jump.

Jeremy Piven may not be giving himself enough credit. On 'Late Show' (Weeknights, 11:37PM ET on CBS), he and David Letterman were talking about dancing. Piven said he had mastered one dance move in the late '80s, 'The Worm.'

Letterman kept hinting around that he wanted Piven to give a demonstration, but Piven wasn't going for it. "If I did it now I'd hurt myself."

But then the crowd got behind Letterman, and put the pressure on Piven. "Can't really disappoint them now," Letterman goaded about the growing clamor from the studio audience.

"I'll warm up and we'll see what we got," Piven said. He then dropped into the splits, and we're talking all the way to the ground. This was impressive for two reaons. One, that he had that kind of flexibility, and two, that his pants had that kind of flexibility.

Neil Patrick Harris has found the perfect role for the two new little bundles of joy in his life: Party props!

The 'How I Met Your Your Mother' star took a break from rehearsing for his upcoming Tony Awards hosting gig to stop by 'The Late Show with David Letterman' (Weeknights, 11:35PM ET on CBS) and shared a few quirky but adorable glamor shots of his baby twins.

"I'm aware of ghosts," Ben Stiller said on 'Late Show' (Weeknights, 11:35PM ET on CBS). This was David Letterman's response: "Wait a minute, stop right there. When you say ... you're aware of ghosts?" The host then paused, looking confused.

Yes, Ben Stiller kind of believes in ghosts. In fact, he was raised in a house in Nantucket that was supposedly haunted by the ghost of a dead baby, which came in handy when the teenage Mr. Stiller wanted to blame someone else for his own infractions. "Lose your wallet? ... Oh, the ghost baby did it. ... My dad would go, 'I smell pot.' The ghost baby [did it.]"

We all have our own Christmas traditions. Some families open a single present on Christmas Eve, some families wait until the morning. Some people have ham for their Xmas meal, others have turkey. Colored lights versus non-colored lights, tinsel versus no tinsel ... there are lots of different traditions.

On the new 'Late Show' (weeknights, 11:35PM ET on CBS), David Letterman showed off his own unique holiday tradition. Once again, toy expert Shannon Eis appeared on the show, and let Dave try out the season's trendy new playthings. One of the toys: a $400 electric go-kart.

The host jumped into the go-kart and put his foot on the gas. "There's no reverse?" he asked. Oh, that wouldn't be necessary anyway. After all, Dave had a ticket to ride, and he didn't care. He hit the throttle and spun around the stage, nearly colliding with his cameraman -- then rammed the kart directly into a 15-foot-tall Christmas tree, which collapsed, scattering ornaments everywhere.

In the new Western 'True Grit,' Matt Damon's character gets injured while being dragged behind a horse, and nearly bites off his tongue. So, Matt needed to find a way to imitate the sound of a speech impediment. "So I thought, well, what if I wrapped -- like -- a pony tail around my tongue," he said.

Which is a bit of a mental leap, but okay. And for the record, by "pony tail," he's referring to a hair-tie, or a "scrunchie" -- not anything to do with actual horses. On the 'Late Show' (weeknights, 11:35PM ET on CBS), Damon invited David Letterman to join him in the unique practice of talking with a hair-tie on your tongue. "I brought one for you," he said. "Did you bring two? Or just the one?" the host asked.

"Just the one ... it's got lint on it," Matt replied, reaching into his pocket. (That's not very sanitary, Matt!)

On 'Late Show' (weeknights, 11:35PM on CBS), we got to see a moment from the past. But this moment also provided a glimpse of the future 'Late Night' wars.

David Letterman's guest was his pal Tom Dreesen. Tom is a comedian who helped Dave out -- back when Letterman was just a 20-something, struggling stand-up comic. Tom got his friend a job on a never-aired NBC game show called 'Word Grabbers,' shot all the way back in 1976.

The young Letterman was hired to play a "celebrity" panel member, even though no one really knew who he was. ... And now, thrill to the sight of a mid-1970s David Letterman: complete with sideburns and an ugly, 'Saturday Night Fever'-style polyester shirt!

Actor Paul Rudd was shooting his latest film in Washington, D.C. While he was there, he ran into our nation's president -- and things went downhill after that. Paul was shooting 'How Do You Know' -- a movie where he plays a corporate executive. He and co-star Reese Witherspoon then went to the White House, where they met President Barack Obama.

So, what was that like? On 'Late Show' (weeknights, 11:35PM ET on CBS), Paul gave us the straight dope. While talking with David Letterman, the actor discussed a tale of ritual humiliation that took place within the Oval Office.

As soon as he met President Obama, Paul broke out into a "flop sweat." Then, the president asked what his role was in the movie. "I'm playing this guy," Paul said. "He's getting indicted, his whole world is falling apart." " ... Oh, so you're playing a Congressman," Obama said.

Having people leave the room while you're talking is generally considered to be a bad thing. But Bill O'Reilly always tries to look on the bright side. Two months ago, back in October, O'Reilly got into an infamous yelling match during a live filming of 'The View,' which culminated in co-hosts Whoopi Goldberg and Joy Behar walking away in protest.

On 'Late Show' (weeknights, 11:35PM ET on CBS), David Letterman had this question for O'Reilly: "What the hell happened over there on 'The View'? What was going on?"

Bill said he knew Behar didn't like him, and that Whoopi's opinion of him varied. He added that he was just trying to "sell a book" during his time on the show. And he found a positive aspect to the fiasco, joking that it was the "greatest thing ever." "You know what I was thinking? ... 'I hope they all leave! Then I'll take the whole show. I'll have 45 minutes of ABC airtime.'" Well, that's one way to sell a book.

If it's the end of the year, then it's time for a Barbara Walters Special. Since 1993, Ms. Walters has used her Oscar special to talk with the "10 Most Fascinating People of the Year." But now, that's coming to an end: Walters said that 2010 is the last year for her special interviews. On the new 'Late Show' (weeknights, 11:35PM ET on CBS), Barbara and David Letterman debated her final "most fascinating" selections, and exchanged some sarcastic remarks.

Letterman started reading off the list: "Betty White -- fascinating. Justin Bieber -- ennnhhh," he said. Walters rushed to the young singer's defense: "If you're a twelve-year-old girl, you love Justin Bieber!" Then the pair moved on to Barbara's other controversial choice: Sarah Palin, who's making a third appearance on the special.

On the new 'Late Show' (weeknights, 11:35PM ET on CBS), Johnny Depp cracked up while discussing a sexy scene involving himself and Angelina Jolie. Still, for some people -- possibly including Depp's girlfriend -- this might not be a laughing matter. And things are made more complicated by the fact that Depp has worked with Angelina's partner, Brad Pitt.

Johnny and Jolie co-star in the upcoming thriller 'The Tourist.' Depp's latest film contains a link to his first major acting job -- his role on the 1980s teen drama '21 Jump Street.' Mr. Brad Pitt was on that show too (here's a fairly hilarious video featuring the two of them). But all of that was a long, long time ago ...

Actor Ray Romano has been married for 23 years now. But he still hasn't learned the key to maintaining a relationship, which is this: Never answer a hypothetical question. Actually, it's probably smarter to not answer any questions. "Do I look fat in this?" "Do I look good in this?" "Where do you want to eat tonight?" These are all potentially bad topics -- still, you have to talk sometimes, so try to respond positively if these subjects come up.

But hypotheticals are especially bad. And on 'Late Show' (weeknights, 11:35PM ET on CBS), Ray tells David Letterman how a "simple" abstract discussion about a threesome led to major trouble. Romano's wife Anna wanted to know this: If you were going to have a threesome involving my friends, which friend would it be? The correct reply here, of course, is: "None of them, honey, because I love you too much."

It's been a while since Jerry Seinfeld has done live comedy. But on 'Late Show' (weeknights, 11:35PM ET on CBS), he cracked some jokes, discussing the difference between the terms "this sucks" and "this is great." His theory -- there is no difference!

If, say, you're eating an ice cream cone, and the ice cream falls off and hits the ground -- then your reaction is "Sucks!" And what do you say out loud? "Great!" (In a sarcastic tone, of course.)

The beauty of the "sucks" equals "great" equation is that it applies to almost everything. For instance ... performing in front of the President. As Jerry told David Letterman, he recently did his act at the White House -- for an event honoring Paul McCartney. Seinfeld is a fan of Obama and The Beatles, so this was a big deal. But would it suck or would it be great?

Actress Natalie Portman started dancing lessons at age four. Still, she wasn't quite ready for her performance in the upcoming film 'Black Swan.' In the film, Natalie and fellow actress Mila Kunis play rival ballet dancers. But even after undergoing ballet training for six months -- for five hours every day -- Portman still got injured.

On 'Late Show' (weeknights, 11:35PM ET on CBS) Natalie described her injury to David Letterman -- and explained what she had to do to get medical treatment. Portman was hurt while being lifted in the air by one of her dancing partners. The actress "dislocated a rib -- it sort of went under another one." "Whoa," Letterman said.

Natalie then asked the producer if he could get a medic to give her "an ice-pack or an Advil or something." But as it turned out, the film was so low-budget that they didn't actually have a medic. Whoops.

Singing is big these days. Well, actually, singing has always been kind of "big," since it's a universal human activity dating back to the start of recorded time. But singing on TV is currently hip, due to the success of 'Glee,' and other shows; shows like, well ... okay -- basically it's just because of 'Glee.'

On the new 'Late Show' (weeknights, 11:35PM ET on CBS), comedian Jim Carrey tried branching out into a vocal career, with mixed results. "I've been tryin' to learn how to sing!" he said. "'Cause it's a sensation!" Next, the comic launched into a rendition of the classic 80s song 'Take on Me.'

Jim screeched such lyrics as "I'll be coming for your love -- okay?" But it was definitely not okay -- as David Letterman's horrified reaction showed. Dave soon had another reason to back away in fear. By the end of the song, Carrey's off-key vocal stylings caused a coffee mug to shatter (sort of).