The sixth season premiere is still months away, but one of last season's bigger Grey's Anatomy cliffhangers has already been resolved. Sources have confirmed to Entertainment Weekly the following: T.R. Knight's wish to be released from his contract has been granted.

He will not return to the show.

The official decision, according to Michael Ausiello, came down in the past few days, just as many of his castmates began receiving their formal pickup letters from ABC.

The actor's exit closes yet another rocky chapter for the embattled show, one that opened with Isaiah Washington-gate and worsened when, amid rumors that Knight was clashing with series creator Shonda Rhimes, George O'Malley was back-burnered.

Finally, Knight grew so fed up with his character's lack of storyline that he asked if he could check out three years before his deal expired. After that, indications were that he would be let go, although Rhimes didn't make a final decision until recently.

Contractually speaking, she had until June 30 to make up her mind.

Last month, Rhimes said George's relatively light storyline this year was the result of the normal "ebbs and flows" of ensemble television. But Shonda did acknowledge that he was intentionally written lighter during the last half of the season.

That way, viewers wouldn't think it odd that he was absent from the season finale - something that was necessary to preserve the episode's biggest twist: that George O'Malley was actually the disfigured John Doe who had been hit by a bus (above).

"I really wanted you to not notice that he wasn't there for most of this episode," she said. "I don't think anybody noticed because of the way we laid it out this season."

TR Knight's departure would seem to indicate George's demise as a character, however, some fans have wondered if Rhimes is planning to pull an Elizabeth Reaser (Jane Doe/Rebecca from Season Three) and have him live, only to be replaced by another actor.

That's "hilarious, ridiculous," the boss has said.

However, rumor has it that Rhimes was indeed interested in having Knight appear in next season's first three episodes, but a short-term deal could not be brokered.

Reps for Knight and ABC declined to comment.

Now that the question of George O'Malley's future seems to have been answered, albeit sadly, another puzzler moves to the forefront: What's going to happen to Katherine Heigl and Izzie, whose life also hung in the balance in last May's capper?

Sound off on both topics below ...

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.