I think AR for table top gaming could be huge, even turning Minecraft into a Lego like game. I'm not entirely convinced of many other use cases in gaming though.
Also, as I said, I think the safety factor of AR pushes it to be more useful in "full room" games than opaque VR, and there's a lot of room for interesting games in that space, and probably a higher ceiling in terms of interested players in AR than in enclosed VR because of the safety/motion sickness/etc issues.