User blog comment:Damac1214/Why Call of Duty is Call of Duty, Fallout is Fallout, Halo is Halo, and that they aren't going to be changing anytime soon/@comment-4279007-20130313220513/@comment-1187559-20130315153035

Bethesda claimed ages ago they wanted to make more than just Fallout 3, even if they've not teased much it's highly likely they're working on it. It's likely taking a bit longer as they'll want to use Creation as opposed to Gamebryo. Another thing you'll notice is in Skyrim DLC they test out a new feature of the engine, so chances are once we're near the end of the Skyrim DLC we'll hear more about Fallout 4.