I saw it on Sunday in 3D and it was a great movie. I prefer not to watch 3D as the glasses annoy me as I have to place them over my normal glasses (one of the reasons I'll never buy a 3D tv at home) and I also find that the glasses also tend to make the images duller which is very annoying for movies that have a lot of night or dark scenes.
The movie itself was definitely awesome, just proving that Marvel comics transfer very well into movies