This movie cleared up a number of things which also opened the door to a possible follow up. The addition of supporting characters was clean as was the explanation of Wolverine's abilities. The ebb and flow of the movie made sense and the time in the theater passed easily.
It also left great questions for follow up. It would have been nice if they had kept the younger version of storm in it (you would have noticed her in earlier versions of the trailers). Overall, it was a solid start.