Chris Evans has signed on to play the title role in Captain America. Evans is of course best known for playing another Marvel superhero, the Human Torch of the Fantastic Four. Evans made for a pretty good Johnny but Cap is a very different role. We'll find out if he has the chops to pull it off when the movie is released next year.
Still not as weird as Deadpool being Hal Jordan.
Quick update @ 5:08 PM: I think I hit that "Publish" button too soon because more thoughts on this have been sinking in.
One important bit I neglected to mention is that Evans would also be playing Cap in 2012's Avengers movie. I wonder how he'll play off Robert Downey Jr. as Iron Man and Chris Hemsworth as Thor. So the cast will consist of a veteran actor, a rising star and an unknown. This makes me all the more intrigued about Thor. I don't have any expectations about Hemsworth or how he'll be as Asgard's favorite son.
Here's a useless bit of trivia. Chris Evans has brown hair and in the comics Johnny Storm and Steve Rogers are both blond. He didn't dye his hair for the former role and I don't expect he will for Captain America either. Interestingly Jessica Alba who played his sister in the Fantastic Four movies did dye her hair blond. I suppose hair color is considered more important for female characters then.