According to VGleaks, the new Xbox will have all of your games installed onto the HDD and here’s the bad part. You can’t play the games on the disc itself!
Now this may sound like a terrible idea, but there is some sense in it being as it will speed up the loading times of games as a standard, in the XDK (see below) it will have a big enough hard drive to store multiple games, but I know someone who has quite literally, a shed load of Xbox games and no hard drive would ever be big enough for the amount of games he has! ( I’ve tried converting him to PS3, but he’s having none of it).