You do realize that I ended up repeating myself the entire time, right?
Everything started in Post #213 and ended back again at the points that I made in that post. Wandering off to AMD/ATI didn't get anywhere.
Apple is in a very tough spot since MCP79A powers everything short of the Mac Pro. There's no future successor for it on Nehalem/Westmere.
Thats nice,
I've noticed that AMD isn't an option to you because you're being pessimistic. If your option might not work, go with the alternative. Thats why Apple went from PowerPC in the first place. If the intel route proves to troublesome for the effort. Go a different way.