"IGN: One thing that’s interesting about the alternate universe/timeline in Days of Future Past is that it could potentially give you the opportunity to revisit things that happened in the third film in terms of characters and endings that you might like to see changed.Best bit? The journalist's polite way of suggesting X3 is rubbish and Singer's near acknowledgement in indicating that s**t needs fixing. Oh and the use of the word "fixing". At this point, what we really want is the narrative ability to have the sequel that X2 promised rather than what we have.
Bryan Singer: You mean, what you’re politely saying is, “fix s**t.” Is that what you’re saying? That’s what I’m hearing. [Laughing]
IGN: [Laughing] Maybe…
Singer: There’s going to be a little of that, a few things I can repair.
IGN: Are fans going to be pleased with these things you will be repairing?
Singer: I think so, I think so, yes.
Film Bryan Singer has given an interview to IGN and they flat out ask him the question. Here's his response: