If this will happen, I'm sure Apple's going to also add in an HD iSight webcam. That'd be cool to do video calls while sitting on your couch in the living room with the whole family.
I'd love this. I could see a commercial around the holidays showing a mother and kids opening Christmas presents by the tree while their deployed father watches via the Facetime cam in the new Apple TV, giving him a living room feel as if he was there with them.