I was going to just let this thread go about its business until Monday, where we could actually hear what is going to happen without continually guessing. But, while we're at it, these are my thoughts on the matter:
Apple is not dropping its PPC architecture for x86 architecture. Switching to x86 would be bad on so many levels because the current sales of PPC Macs would grind to a halt and the software developers will cumulatively give Apple the middle finger for making them recompile all the apps after being stroked for years that "PPC is the future."
Who knows if IBM is out of the picture forever.
I bet if Intel is going to make cpus for Apple, they will be some sort of RISC architecture that will make for a smooth transition with newer Macs down the line. Intel is no stranger to the RISC world. Heck, some RISC has even snuck into the Pentium line. Additionally, Intel has made RISC processors for years, including the StrongARM line. It wouldn't shock me in the least for Intel to rollout a strong RISC processor for Apple. I don't think Intel is married to the x86 design. I think they are married to Windows, which insists running on the x86 design. Intel is semiconductor company, but it's still a business out to make money. The money is clearly in the Windows corner, so x86 is king. However, if there's a niche that needs filling, I bet Intel can fill it with RISC processors for Apple. I'll also bet money that Intel has many "secret" projects, including processors designed for Macs, because every manufacturing company has products that "know their enemy." You never know when you need them, and you can also make your own line of products (in this case, the Pentiums) better by knowing you enemy.