As someone with a keen eye
n developing graphics technology I just don't see how this scenario is really possible. So long as Nintendo aim for a modern 40-50w system at ~28nm and pack in at least 1GB of RAM then they'll handle the vast majority of ports from Microsoft and Sony's systems just fine.
Process shrinks are taking longer and longer, high end GPU power requirements are never going to be feasible for consoles ever again and after the RROD and PS3 cost disasters (both a direct consequence of the unrealistic TDP of launch hardware), the power draw of Sony and Microsoft's machines must come down. Heck, Sony just unveiled a new system comprising of years old off the shelf hardware, their desire to drive thecutting edge of technology is over.