I've been a fan of Captain America.
John Krasinski is NO Captain America.
Please for the love of Mephisto let this be an Internet rumor just like Bat-Boy, Elvis sitings, and Eskimos.
If Marvel wants to keep things simple they should hire Ryan McPartlin from CHUCK (he plays "Captain Awesome" with incredible ease...so he's at least got the military credentials to pull off the role). McPartlin has the voice, build, and charisma to command the likes of Thor and Iron Man as they go into battle against The Hulk...(YES Marvel, make the Hulk the enemy in the movie and half the battle is immediately won!) Based on his acting on Chuck, McPartlin could also play the "awkward man out of time"-role which is also needed since Captain America is frozen in 1941 and then thawed out in modern times.
Fans always cry: MAKE MINE MARVEL!
Well, MAKE MINE McPARTLIN!
I'm attaching this picture of Reb Brown as Captain America for added entertainment value. That shield needs to be blocking something else besides bullets.