We have a section dedicated to using AW with iPhone. You would need to register to post in it though.
That said, it doesn't seem as though anyone has tried it and if they have it hasn't been posted about too much. The good news is that you can try it, report back to us if it works, then revert back to 1.5 if it doesn't. I use my watch with Android and (while tempted) have decided to keep my watch on a production release.