I'd imagine anything that requires gyroscopic motors like what you describe and/or a touch screen will have to have a cord I think.
Well, supposedly, that is one of the reasons it's taken so long to show the controller, as they are trying to get it to run wirelessly with a long battery charge.
Also, I don't think this has limited use like a bongo controller at all. At worst, I think it's just super advanced force feedback. At best, I could be used to actually control many games (if not all games).