After a season and a half on Doctor Who, as well as two Christmas specials and a special appearance on the show in season seven, the BBC has confirmed that Jenna Coleman is leaving the show. Jenna has played Clara Oswin Oswald, one of the Doctor's companions. It's unknown when Jenna will leave the show exactly, but most people (myself included) believe it will be about mid-season, likely when the episodes titled "The Girl Who Died" and "The Woman Who Lived" (episodes five and six, respectively) hit our screens. This is aided by the fact that Clara is well-known for being The Impossible Girl; that is, the Doctor had encountered Clara twice before he found her as his companion, and she died each time.
Jenna made her debut on Doctor Who in the first episode of the seventh season, "The Asylum of the Daleks." She played a crashed astronaut who had somehow survived being trapped on the planet-wide asylum the Dalek race had created for their own kind. However, Clara had actually been transformed into a Dalek for her intellect, but somehow held on to her humanity and was instrumental to the Eleventh Doctor and the Ponds escaping from the Asylum at the cost of her own life.
Jenna's next appearance was in the Christmas special of the same year, "The Snowmen," once again playing Clara. Once again, she died at the end of the episode, this time after suffering a nasty fall. Once the Doctor realized that the Clara from "The Snowmen" was the same as the Clara from "The Asylum of the Daleks," he was motivated to start his travels again to find the Impossible Girl, and she's been with him ever since, even through a regenerative cycle.
I'll be sorry to see Jenna go. Admittedly, Clara isn't my favorite companion (that would be the Ponds), but she did do a wonderful job. I think that Clara was the perfect companion to travel through time and speech with the newly regenerated Twelfth Doctor given her close relationship with the Eleventh. As a few parting words: