Matt Smith is leaving 'Doctor Who' ?

Matt Smith is leaving 'Doctor Who' after four years as the 11th Doctor, the BBC revealed today.

With his third full season as the Doctor ending last month, Smith will return this November in the show's 50th anniversary special before bowing out during the annual Christmas special in December. 

That show will likely conclude with the Doctor regenerating into the form of the actor who takes the part next, and speculation is sure to begin almost immediately over who that will be. Smith was a relative unknown when he took over from the popular 10th Doctor, David Tennant, becoming at age 28 the youngest actor to ever play the role of the centuries-old Time Lord. His companions have been Amy Pond (Karen Gillan), Rory Williams (Arthur Darvill) and most recently Clara Oswald (Jenna Coleman). During his tenure on the program, "Doctor Who" has become more popular than ever before, reaching more than 30 million UK viewers while becoming the top-rated program on BBC America here in the US. Smith said in a statement, "Doctor Who has been the most brilliant experience for me as an actor and a bloke, and that largely is down to the cast, crew and fans of the show. I'm incredibly grateful to all the cast and crew who work tirelessly every day, to realize all the elements of the show and deliver 'Doctor Who' to the audience. Many of them have become good friends and I'm incredibly proud of what we have achieved over the last four years." He added, "The fans of Doctor Who around the world are unlike any other; they dress up, shout louder, know more about the history of the show (and speculate more about the future of the show) in a way that I've never seen before, your dedication is truly remarkable...It's been an honor to play this part, to follow the legacy of brilliant actors, and helm the TARDIS for a spell with 'the ginger, the nose and the impossible one'. But when ya gotta go, ya gotta go." "Doctor Who" lead writer and executive producer Steven Moffat said, "Every day, on every episode, in every set of rushes, Matt Smith surprised me: the way he'd turn a line, or spin on his heels, or make something funny, or out of nowhere make me cry, I just never knew what was coming next. The Doctor can be clown and hero, often at the same time, and Matt rose to both challenges magnificently. And even better than that, given the pressures of this extraordinary show, he is one of the nicest and hardest-working people I have ever had the privilege of knowing...But great actors always know when it's time for the curtain call, so this Christmas prepare for your hearts to break, as we say goodbye to number Eleven. Thank you Matt -- bow ties were never cooler." In related news, former "Who" companion Karen Gillan has reportedly landed the role of the lead female villain in next year's Marvel movie "Guardians of the Galaxy." The Hollywood Reporter broke the news of Gillan's casting, although the name of the character has not been revealed.

She'll join Lee Pace and Michael Rooker as potential evildoers in the film, while the Guardians themselves will be played by Chris Pratt (star-Lord), Dave Bautista (Drax the Destroyer), Zoe Saldana (Gamora) and whoever voices the sentient tree Groot and talking animal Rocket Raccoon. John C. Reilly and Glenn Close were also reported last week to be close to signing onto the film, which director James Gunn will begin shooting later this month in the US.