Tonight's round of casting news goes from Appleby to Bieber, along with a few more stars in between. Shall we? 

Hill and Bieber to host Saturday Night Live: The Huffington Post reports that this 2012 season, the show's getting even bigger names. Alec Baldwin's podcast was the first to confirm the gigs, even noting stars like Ben Stiller and Katy Perry. But the real news is that Jonah Hill will definitely appear on the March 10 episode. As for Bieber, he hasn't "officially committed" to be both host and musical guest, as Baldwin claimed. Watch out for it anyway.

David Arquette and Courteney Cox reunite: According to The Hollywood Reporter, ABC has revealed the inclusion of actor David Arquette in the Cougar Town season 3 finale. He'll be playing a very helpful hotel concierge and will be joining his wife, despite being separated from her since 2010. 

Franklin and Bash and Appleby: TV Line has confirmed that Life Unexpected actress Shiri Appleby has landed a multi-episode arc in the second season of the TNT series. She'll be portraying a "smart and sassy" associate who gets romantically linked with Jared (Breckin Meyer).

Matt Lauria becomes a Person of Interest: Another piece of casting news from TV Line concerns one Friday Night Lights alum. This February, catch Matt Lauria play "a sharp, young trader at a major investment bank". He'll be appearing on episode 16 of the CBS drama.

The Good Wife welcomes Gummer (again): We last saw Nancy Crozier in season 2's "Getting Off", and now Mamie Gummer is returning for another appearance. According to the Huffington Post, she's going against Lockhart/Gardner by standing up for the family of a suicide victim.

Weisman goes from Alias to Awake: Kevin Weisman has reportedly been cast as a character named Mr. Blonde on the NBC series. EW.com confirmed that his role is a haunting one: "A man with unclear motives, it seems Mr. Blonde has revealing information about the car accident that changed Britton's (Jason Isaacs) life." Since there's no premiere date for Awake yet, you better stay tuned for more updates about it.

Ken Marino is one of The Exes: On the season finale of the TV Land comedy, Party Down star Ken Marino makes an appearance as Brad. He's Holly's (Kristen Johnson) former fiance who cheated on her, and now she's trying to prove to him that he's moved on. Check out the clip here and catch The Exes this Wednesday at 10:30pm.

If you're hungry for more casting bits, don't miss this one about Kim Kardashian on Drop Dead Diva. We also hear NCIS star Sarah Jane Morris and The Vampire Diaries actor Taylor Kinney are heading for Castle!