well, Nintendo can't sue them until they see the final product, take it apart, and see if it infringes on any of their patents. So we could see this hit store shelves, then a suit start, then it get pulled (nyko nunchuck thingy had that happen)
As for if there is a nunchuck or not, it is strongly rumored, and Sony can't keep a secret to save themselves, so I wouldn't be surprised if we see one soon.