I had a mixed reaction to the twist at the end, but I've decided that I don't hate it. It is weird seeing this cast of characters phoenixed up, but in a way it does make sense. I do like that through this weeks Uncanny X-men and Avengers vs. X-men the phoenix force is developed a little. While we've always known that its a cosmic entity, and Grant Morrison wrote that it "burns away what doesn't work," the phoenix force was always vague. Now we know that the phoenix force is a guardian of evolution, and Unit gave us a solid example clearing up the role it has played. And we also know that the Phoenix force is here to restore mutants... making Cyclops right?
Also, using the X-men as agents of the Phoenix fits into Grant Morrison's depiction of the phoenix using multiple different hosts across time and space to fulfil its purposes, so that feel less random to me. I love Cyclops' costume... but not really any of the others.
So... if the Avengers hadn't been involved, the phoenix force would have possessed Hope, who would have been surrounded by her Lights, and she would have reversed M-Day...