No Fallout 4 reveal then :(
No, they spent a shit ton of money getting the rights to fallout. They are working on fallout 4. And it easily has the potential to sell as well as Skyrim.
Maybe after the insane success of Skyrim the what they wanted to work on next, possibly shelving F4 for now or passing it on to someone else.
Next Fallout game by Obsidian is actually a possibility now. Not that I cared who made the next Fallout anyway.
The only thing I can think of is they want to get Skyrim sales, but don't want to release it on last gen consoles because it would be stretching them too thin. So they are waiting for the install base to grow.
I do hope Obsidian has some part in FO4. Storywise it was miles ahead of anything that Betheda has done, and I actually think Bethesda's stories are pretty good.