I saw the movie myself last friday. Loved it! The action-y bits were quite impressive, but nothing's better than the heroes giving each other a hard time. Hehe. Was a bit worried all those heroes in one movie wouldn't really work, but it really did. It does help if you've seen the previous Marvel movies, of course, but it does work on its own.
Gotta say, Hiddleston's Loki is an amazing villain. I hope he sticks around for Thor 2 and Avengers 2 if that ever happens.