My wife and I saw it on Saturday, and both loved it.
Again it falls into the Super Hero Sequel trap of too many bad guys/good guys, but they pulled it off. I wasn't confused at any point who someone was, or whose side they played for, which for an action/super hero movie is just fine.
Overall highly entertaining, good dialog, and a definite Buy-on-BR-Release day for us.
/*New and stirring things are belittled because if they are not belittled, the humiliating question arises, ``Why then are you not taking part in them?'' -H.G. Wells*/