Well here is a guy that actually made something that seems to fly quite good.
Could use a better paintjob and a more realistic cockpit and so on, but as an airframe it does look like an Xwing.
Made out of two $35 HK Radjets:
https://www.youtube.com/user/kedelbach/videos
So if something as simple as this can fly without canards and just a pusher prop....well Josh and Peter definitely are the ones that can pull it off and make a foam kit out of it
I just whish one of the crew would reply to this thread. It's getting closer to the movie release, so let's all hope they just give us SW-fans a reply. would be nice