^Bridging to PC development opens the doors to an enormous treasure of know-how. People who spent years developing multithreaded engines and games of bigger scale than anything that was possible on earlier consoles. People who routinely wrote network code and complex AI code and better physics.
This is basically where MS aimed for the performance of the 360, and there was not much space to further cut costs. Fall short of reaching those developing resources and you're losing a lot in terms of the value of your upgrade investment.







