As with all rumors, take the following story with a grain of salt until we can receive official confirmation or denial from either AMD or IBM.
Whenever AMD shares are low enough the buyout rumors begin. The name IBM is often tossed around as a potential buyer, but it seems unlikely considering their focus on software over hardware recently. Still, the rumors persist based on IBM's manufacturing capacity and a few joint-venture research projects.
“IBM of Armonk, New York, has had a research and development expense-sharing agreement with AMD, and analysts have speculated that AMD might want to use IBM's East Fishkill, New York, chip-fabrication plant to build microprocessors.”
If IBM does decide to get back into the game, it seems that they'll probably be lamenting the choice to offload their hard drive interests to Hitachi and their PC business to Lenovo.