Not sure if this has been a thread already, but I say they should for one simple reason: As long as it stays working, it would give a fresh start in their reliability reputation.
It doesn't matter how much the system now works, there is still the breakdown stigma, that still keeps some customers away, particuluarly in Japan.
Now there is the issue of fitting the HDD, but I would just have it the new model have a dock on the top (as in the top when it's horizontal), that's a little sunken in. If the new model is stilm enough, it would effectively be no thicker than the current 360.
A flashy-first game is awesome when it comes out. A great-first game is awesome forever.
Plus, just for the hell of it: Kelly Brook at the 2008 BAFTAs