Bad news for ABC — better news maybe for Ellen Pompeo and Patrick Dempsey: Sandra Oh has announced she’s leaving Grey’s Anatomy at the end of the ABC drama’s upcoming 10th season. “It’s been a great privilege to play the character of Cristina Yang on GA and I am both sad and excited to see where this, her final season will take her,” Oh said in this afternoon’s statement, calling it an emotional and “deeply creative decision” to leave.

Pompeo and Dempsey’s contracts also are up at the end of the coming season, and ABC presumably won’t want any more of the series majors to exit. That’s always a good bargaining position. Dempsey made news the recent Summer TCA Press Tour, when he told a ballroom full of press — while promoting a car-racing show for Velocity network called Patrick Dempsey: Racing Le Mans – that his passion in life is car racing, and acting is what he does to support that habit. Some mention may have been made of the redundancy of Grey’s storylines. Eyebrows around the room shot up. And a few days later, at the Press Tour, the reporters asked ABC programming chief Paul Lee if Dempsey was leaving and/or Grey’s was toast after this season. Lee responded, emphatically — as did ABC today in the wake of Oh’s announcement — that ABC intended to have the steamy doc drama on the primetime lineup “for many years.” At that time, Lee said he would not discuss possible cast changes — the press assumed he was talking about Dempsey — because he didn’t want to be yelled at by show creator Shonda Rhimes.

Grey’s, even nine seasons old, is an important ranchise for ABC. It was TV’s No. 1 broadcast drama of the season in adults 18-34 and across all key female sales demos. It pulled in a very upscale audience. And, like Lee said, it’s a DVR fave: Original episodes added about 3.5 million viewers to its first reported stats when DVR viewing up to 7 days was factored in.

Speaking of Rhimes, this afternoon she said, “One of the best days of my life as a writer happened the day Sandra Oh walked in my door to audition and forever changed the course of Grey’s Anatomy with her brilliant, nuanced portrayal of Cristina Yang.” Rhimes promised Oh’s character would be given “the exit she deserves” — which, as longtime fans of the show can attest, could go either way.