I would love to be able to play PvE WoW on a tablet, but I would still need a mouse..... I don't do well with controllers. I know that I once saw a guy showing wow being played on an iPad, but I don't recall how or what he did. The video was just to show that it was possible, even though he admitted it was not good.
But I would love to play on a tablet for basic leveling.... I could put the tablet on my exercise bike's tray, and burn calories while questing!