Everyone seems to expect them to make you smash the control around to do moves, and they might, but I think it's more likely they'll just use it for items and things like that.
For example, items you throw you could pick them up with the B trigger and hold it, if you just release the trigger you drop it, but if you release it while swining your controller slightly in a direction, depending on the speed and angle and stuff you can throw it where you want. For weapons you fire you could point at where you want the shots to go. Perhaps new items were you have to point at another character and it'll home in on them so long as you're accurate enough to get them spot on, otherwise it just attacks where you pointed, regardless of if anyone is there.
There are other things like tilting the controller sharply one way or another to dodge an incoming item, but I don't personally expect many if any main attacks to be done with movements. We'll see.
