You really, really, REALLY don't want developers making those kinds of hacks that work around APIs. In an ideal world, we're rely even less on hardware than we do now and target nothing _but_ APIs, such as by shipping all "binaries" as LLVM bitcode files that are JIT compiled to the native machine code just before execution (just like our graphics APIs do now). Or just shipping C#/Java, except some mythical version of those that doesn't suck donkey-nuts for systems/games programming.
No, no it absolutely is not. Microsoft did register a trademark for the name "Fusion." By definition that cannot be the same thing as AMD's Fusion, or Microsoft would not have been able to register a trademark for the name. The odds of any console ever using any x86-based CPU ever again is slim to none. You can bet that AMD GPUs will be in the next wave of consoles, and you can bet that IBM's CPUs will be in them (though I'd also be willing to bet that an ARM CPU may be in at least one of them).Then again AFAIK the next gen xbox will use Fusion.