blauboad, chipguy, who says IBM is going to fab for AMD? Last that I looked they have a joint development agreement for 65nm, and a technology exchange for 90nm. There are lots of ways that joint development can go - for instance, how about a jointly owned factory?
Another possibility is that IBM may want to second source K8 processor production for their own product.
However, first they need to successfully produce a competitive 65nm pilot line, then we can talk about all sorts of business deals.