AMD must survive
I think that Intel has a stake in keeping AMD alive, so that they can claim that the CPU market is still competitive. It's no longer competitive in terms of product offerings, because the "Intel Architecture" has cleaned everybody's clock. Even Apple recently gave in and switched to Intel chips from Motorola and IBM. The only way to have competition is to have more than one company producing the standard design.
It's like when Bill Gates invested $200 million in Apple. He didn't do it because he wanted to make kissy-face with Steve Jobs, they hate each other; he just needed Apple's 5% market share as a defense against antitrust regulators.