Those current gen console gamers buying Far Cry 3, Fifa, COD, Halo, and Assassins Creed there aren't going to suddenly stop gaming when devs all move to the new boxes.
I think there's a potential catch 22 situation there though. Particularly for FIFA and COD, I can see a situation where EA and Activision don't fully abandon current gen until gamers move en mass to new hardware, and where gamers don't move en mass to new hardware until EA and Activision essentially abandon current gen.