Rumor has it that Dr. Erica Hahn won't be the only regular character leaving the show this season. Part one of "Callica" is also scheduled to exit Grey's Anatomy around episode 15!
According to AfterEllen.com Melissa George's character has been brought in for Mark Sloan, so is she who they're replacing Sara Ramirez with?
Note: the lesbian-intern-storyline concerning Callie has been erased from the upcoming scripts. Hmmm
UPDATE: there has been confirmation that this is just a rumor but then again you should check in once a week for the remainder of the show's run. You know, just to be safe.