I don't have time to read the other posts (just now)...
but for me, it was a big disappointment of highexpectations.
it just felt bland and without the spirit that Bryan Singer had with the X-Men movies.
I was VERY excited to know he was working on it...I really felt that his X-Men movies really brought the spirit of the comics, while modernizing and "movie-izing" X-Men so it can appeal to both fan and newbie. There were nuggets than fans could appreciate, but didn't alienate ,let's say, kids who never read X-Men before.
Superman Returns just didn't feel like any of that.
I also feel sad that Singer dropped X-Men 3 to work on this -- it made sense to me (I might have done the same thing given the opportunities), but the result were TWO superhero movies that weren't very good, rather than at least 1 that would be been a great segment in the x-men trilogy