Guest Star spoilers

Future episodes will see the return of some of your old favorite [grad students], including Wendell Bray, Daisy Wick (the girl who sucked up to Brennan), Clark Edison (the guy who didn't like sharing personal information) and Vincent Nigel-Murry. [...] Marisa Coughlin has been tapped to guest-star in a midseason episode of the hit Fox series. Coughlin will play Payton Perotta, an FBI agent who is brought in to crack a case after Booth has to remove himself. As part of her already tricky task, Perotta will have to interrogate none other than Booth. Also appearing in the episode (and boasting a more direct link to its title, "Fire in the Ice") will be ice hockey great Luc Robitaille, playing himself. Source: TV Guide Online

Andy Richter has signed on to guest star in an upcoming episode of Bones that takes viewers behind the scenes of the greatest show on earth-- the circus! The plot finds Booth and Brennan working undercover as a knife-throwing team named Buck and Wanda (love it!); Richter plays the circus' owner-ringmaster. The episode is slated to air in January. Source: The Ausiello Files

I'm so excited for both episodes!!!