The BBC has announced that Jenna-Louise Coleman has been cast as Doctor Who’s new companion for the 50th anniversary year of the show.  Coleman will play against 11th Doctor Matt Smith, replacing Karen Gillan, who’s leaving the show with Arthur Darvill later this year.  Coleman is probably best known to North American audiences for her role in Captain America:  The First Avenger.

The 14-episode seventh season is currently shooting; it sounds like Coleman will be introduced during this season, with her first full season in 2013, the 50th Anniversary year.  The sixth season in 2011 was presented in two half-seasons (see "Two 'Doctor Who' Seasons").