Huh?? Maybe I am misunderstanding here but I never had to plug my 360 controller into the console to get it to work. Also is there actually people that do not turn on their 360 with the controller (accomplished by holding the big 360 button)? I don't think I have touched my 360 power button...
I doubt cube games will be downloadable. For something like RE4 it would be over 2 gigs most likely since it comes on two disks and the disks hold 1.8Gb. I would guess they will release only up to the N64.