It depends on how they play. The goals seem to have dried up on Team USA at this point, and I think that this goes directly with the shaky goaltending. Everyone knew that the weakness of Team USA was going to be the defense but with the good goaltending on good shots and bad goaltending on weak ones, that is going to be eating away at the back of the minds of the players. If Montoya can turn on the lights upstairs and make a couple of good saves early on then the US will run away with the game, but if he lets in an early goal Sweden's confidence will surge and they will "upset" the US.
I'm having a hard time predicting specifically who will win because I just don't know what Montoya will show up. I don't know enough about him as to whether he can just turn it on at the last minute in a tournament like this because he was dominant the whole way through last year.
I'll say Team USA wins 4-2 with an empty netter, but if Montoya struggles it will be 3-1 Sweden.