I kinda hope Nintendo just ditches AMD to be honest.
PowerVR can give them better performance per watt at likely a lower price.
The GT7900 could give them 800 GFLOPS on the console variant at under 10 watts and can scale up even further if they want. A mobile version of the same chip could be in the 400 GFLOP range for 5-6 watts and give them a very powerful handheld.
I doubt AMD can beat those performance ratios, if they could they would be making GPUs for tablets/phones and be a big player in that scene, but they're not.
Make smart decisions with the hardware, IBM/AMD sure as heck aren't helping Nintendo now, they're stuck with a bloated custom design that they can't lower the price on. Use a more mainstream vendor like PowerVR IMO. They make the Apple iPhone/iPad GPUs so you know they operate on a huge mass production scale.