I guess my biggest problem wasn't the length of the black, but that I wanted the credits to start rolling closer to when the music started up. I understand wanting to make the audience think about stuff, but when they start wondering if the theatre screwed up I think you've missed the mark.
I saw it this weekend with the wifey and several friends. I thought it was great. Mickey was perfect.
I agree with halsteadfrost about the ending, way too long on the black. I like the ending after thinking about it. At first I really hated it. I still think the ending ruined the movie. Also, there was too much wrestling in the beginning. Otherwise it's great.