Actually, I have to disagree with you there Emmie, Captain America is one of the safe bets for comics, I mean its World War II - Its not too hard to make up a solid WWII movie. Comparing that to Thor or Hulk, I'd say Captain America is the easiest of them all.
I just hope its not another Ironman 2, where I enjoy the movie, but not for its action (Seriously, Ironman 2 had such little action, it was shocking)
Also, Rumors are that the villain for the Avenger movie is a combination of Loki and the Skrulls. Skrulls are a great villain choice, however I wish they would leave it for a sequel. Though, as long as Super Skrull looks badass, I'm fine with it. There is no solid evidence on this yet, but its enough that some sites have given it solid consideration. So take this news with a grain of salt.