Although 'Thor' has garnered mega-buzz in the weeks that have been leading up to its release May 6 -- the Kenneth Branagh comic flick even has reviewers wondering if it's better than 'Iron Man' -- its franchise future was murky until recently. After all, it's been known for months that Marvel stablemate Captain America was already set for a sequel.

While Stephen McFeely and Christopher Markus, the writers of 'Captain America: The First Avenger' (due July 22), were signed on for the Captain America sequel in February, the real mystery about that project had been the time period in which the film would take place: WWII or modern times.