On a flight a while back I struck up a conversation with a PhD that specialized in chip design. He suggested that if AMD was able to manufacture their chip designs in Intel's fabs, that they would be out Intel chips in terms of performance and power.
The idea was that because AMD uses fabs that are, basically, two generations behind Intel, that their designs have to be more innovative to be able to work within the constraints of the older process.
I'm no electrical engineer, so I took him at his word, but it certain points out that Intel's fabs are a distinct advantage.
Maybe if they partner with IBM. Still, even if Global Foundries is two generations behind Intel, that's still one of the most modern fabs and being constantly updated is very expensive.
Intel is able to field several different processor lines and architectures simultaneously, and also develop multiple new architectures at the same time. That's not something that most other companies can do. They've also been reasonably good at recovering from mistakes quickly (something that Microsoft has also been fairly good at).
That said, it'll be interesting to see how things pan out with the changes to the computing landscape that are in the works now.