We're going to have to wait a little bit longer for Thor 2. Originally it was set for a July 26, 2013 release but Disney has announced that they will release Phineas and Ferb on that date instead (I guess it's based on a Disney Channel series or something).
Where does that leave Thor?
Thor 2 will be released on November 15, 2013. Right now, it seems to be the only big release set for that date. I'd rather my comic book movies not come out during SDCC season. No reason has been given. Let's hope the extra time is used to make the movie kick even more ass than it would have if released earlier.
UPDATE
Patty Jenkins (Monster) will direct Thor 2.