Can't wait for this episode, from the title alone you know it's going to be brilliant. I wonder if it's going to be "doctor lite" and focus on Amy, Rory and River. Will be great to see what their relationship is like now. I have no idea how it's going to fit with the ongoing storyline though.
I don't think there will be gangers involved as some have suggested, the "other Amy" is most likely just a stunt double, for the motorbike scene(s).