If I didn't love this news so much, I'd be worried that 30 Rock was turning into The Love Boat or Will and Grace. After all, it seems as though there's news of a new guest star every few days. First Will Arnett signed on to reprise his role as the delightfully evil Devon Banks, then ex-Friend, Jennifer Aniston, decided to return to television in order to stalk Jack Donaghy. After that came news that Oprah was scheduled to play herself on an upcoming episode.

That's a lot of guest stars to pack into one season, but now we have news of two more. Everybody's favorite Gossip Girls, Blair and Serena, AKA Leighton Meester and Blake Lively, are coming to 30 Rock. What on earth could bring these Upper East Siders to Midtown? Are they trying to overthrow Liz Lemon as queen bee of TGS with Tracy Jordan? Are they starring in a movie with Tracy Jordan? There's more info on their storyline after the jump.

According to sources, the dynamic duo will be appearing in a flashback. Liz is attending her 20th high school reunion and Meester and Lively play her former classmates. It's through these flashbacks that we learn Liz Lemon's deep dark secret: she used to be a Mean Girl! Turns out Lemon wasn't always the "fight for the underdog" type; the high horse she was upon used to be a lot bitchier.

Since Meester and Lively are playing the high school version of their characters, producers are said to be looking for actresses to play the adult versions. In one case, they're not looking very far: Producers may be looking at Blake's older sister, Robyn Lively to fill the role.

I'm kind of surprised that the CW is even allowing two of its biggest stars to make this guest appearance. After all, CW is owned by the same company that owns CBS--not NBC, where 30 Rock airs. However it's working though, I'm just glad that it is. Gossip Girl is such a guilty pleasure of mine, so the idea of putting Blair and Serena on one of my favorite shows? Simply genius.