Today brings hints of a new Fallout game from a source who is actually in a position to know something: Erik Todd Dellums, the voice actor behind Fallout 3's ThreeDog (via All Games Beta). Dellums tweeted to Fallout 3 fans that "there may be more of the Dog coming! Fingers crossed!"
Not exactly concrete info, but Dellums' follow-up tweet is encouraging: "I was given permission to release that tease," he wrote. The last Fallout game, Fallout: New Vegas, was developed by Obsidian Entertainment in 2010, but ThreeDog appeared in Bethesda Softworks' 2008 series revival, Fallout 3.
I'd put the smart money on BethSoft being behind whatever the next Fallout is, given that the current hardware generation has seen the studio alternate between Elder Scrolls and Fallout games. Skyrim was released in late-2011. Will Fallout 4 be revealed, even released, in 2013? We'll have to wait and see.