Maybe Nvidia doesn\'t own the rights on the GPU on their own? If it\'s Microsofts, then I don\'t see the problem of using non-Nvidia production plants to manufactor it. Pretty much depends on the deal Microsoft and Nvidia went in to...
If it does come to this though, I think Microsoft is giving themselves the boot, as Nvidia was the best thing that could come along with Xbox. If they stuff it up, I wonder what will be in Xbox 2...