For all the dimensions that Doctor Who has explored on TV, the third has been a rarity -- there was an early 3D experiment in 1993 for the series' 30th anniversary, a 2010 trailer, and that's that. For the show's 50th birthday, the company is willing to make a return trip through a two-part 3D special. Most of what's in store for the unique event is being kept secret, although we imagine we'll see plenty of Sonic Screwdriver action. We'll have to see how closely the special's broadcast dates align with the official anniversary in November; hopefully, it's far enough in