Collider claims that Feige revealed what's in the vault, but he didn't really at all. He couldn't even clearly recall the objects he did name, though I'm glad they cleared up that it wasn't the Eye of Agamotto.
What Collider *MISSED* as news in their interview is that Marvel has seemingly given up on a second summer 2012 film. They talked about announced more films for 2013, but Avengers will be filming through September leaving no time to rush another film out by the summer. Most films of that size need to start a year and a half early at the minimum, so they're already in a mad rush just to meet their May release date. If they hit any production snags and need some re-shoots or pickups, their entire Marvel cast may need to assemble (sorry!) at any point between October and March for those shots.
ALSO, Feige pretty much confirmed a Namor film is being developed at Marvel Studios. Avi Arad had tried to make it at Universal for years and it only recently reverted to Marvel. If you watch the SHIELD map at the end of Iron Man 2, they even hint at something Avengers-related going on in the ocean.