People will purchase the HDD for the DLC.
The important thing is to minimize confusion for the sales process. In my opinion MS needs the $149 price point this fall. Really can only do that with the equivalent of the arcade model. 4 SKUs will be just to confusing and difficult for retailers.
$149 Arcade equivalent
$299 with Natal
$249 Elite equivalent
$399 Elite with Natal
That is just to many SKUs.
Maybe they up the size to 16GB flash drive. I really do believe that MS introduced the ability to save to a USB device for a reason. They werent really under any pressure to do so.
Its libraries that sell systems not a single game.







