Denise Richards is heading to '30 Rock.' According to E! Online, the actress will appear in the upcoming sixth season.

"So excited!! I'm going to be doing an episode of #30Rock! one of my favorite shows!!!!!" she tweeted.

James Marsden has also booked a '30 Rock' role. EW reports his role could be recurring, but NBC isn't revealing details. Could he be Liz Lemon's new lover?

Richards and Marsden join previously announced recurring guest star Will Arnett on the upcoming season of '30 Rock.' No premiere date has been given, but best guess is it'll show up on NBC sometime in the winter.

In other casting news ...

Two veterans of the 'Battlestar Galactica' universe have landed upcoming guest roles on very different shows.

Jamie Bamber, who played Lee "Apollo" Adama on 'Battlestar Galactica' and went on to appear in 'Law & Order: UK,' will have a recurring role on the new TNT series 'Perception,' which stars Eric McCormack as Dr. Daniel Pierce, an odd neuroscience professor who helps the FBI crack cases.

Bamber will guest at least twice on 'Perception' as a new professor who catches the eye of Kate Moretti (Rachel Leigh Cook), Pierce's FBI handler and former student.

'Perception,' which also stars Kelly Rowan and Arjay Smith, premieres in the summer of 2012. And no doubt Bamber fans are aware that Bamber was also recently cast in a guest role on 'CSI: Miami.' (More nerd-bait casting: 'Star Trek' actor LeVar Burton will recur as a dean at Pierce's university.)

Another veteran of the 'BSG' universe, 'Caprica' actor John Pyper-Ferguson, will have a key role in the season finale of Syfy's 'Alphas,' a drama about people with extraordinary abilities.