Marvel announced Thursday morning that it is rescheduling three of its upcoming films to allow a longer run-up to its Avengers film, which was moved back from July 15 of 2011 to May 4, 2012.  Thor was moved back from July 16, 2010 to June 17, 2011.  The First Avenger:  Captain America was moved back to July 22, 2011 from May 6, 2011. 

Iron Man 2’s release date remains unchanged:  May 7, 2010.

And Marvel confirmed that Spider-Man 4 will release May 6, 2011. 

The changes give Marvel the first weekend in May for the next four years (X-Men Origins:  Wolverine opens May 1st of this year).