It's not going to be easy. I can see him beating Nadal, but not Djokovic or Fed at the USO. If he can somehow improve his second serve I'd say it's possible. His serve (especially second serve) is his biggest weakness. His FH does look better than before but he he still needs to improve that shot too.
and yeah, I'd love to see Andy winning his first slam ... poor guys is so underrated here ...