The Avengers 2 release date announced

An official release date, which is subject to change, has been released for The Avengers 2. It appears we can expect the anticipated sequel. for May 1, 2015.

This is roughly 3 years away but they had to give enough time for the rest of "Phase 2" which is as follows:
Iron Man 3 (May 3, 2013)
Thor: The Dark World (November 8 2013)
Captain America: The Winter Soldier (April 4, 2014)
Guardians of the Galaxy (August 1, 2014)

There are also still rumors swirling around a movie centered around Ant Man directed by Edgar Wright. It is rumored that might have a late 2013 release or an early 2014 release, if it happens at all, but either way The Avengers 2 will be the finale of Phase 2. Guardians of the Galaxy will most definitely be introducing Thanos as a lead into The Avengers 2 so that is going to be bomb.
It was also recently announced that Joss Whedon will be involved with Marvel and The Avengers through 2015 so it's pretty safe to say he will be back to direct The Avengers 2.