CNet provides some followup on nanotube and liquid-cooling technology.
Specifically they mention a startup named Cooligy. According to Cooligy's vice president of marketing, they expect their liquid cooling system to be used in a "workstation" this year.
Rumor-readers should recognize this company's name. In October 2003, Cooligy admitted to creating prototype designs using their technology for a number of companies -- including Apple. In November more specific rumors emerged of a liquid-cooled PowerBook targeted for 2004.
Meanwhile, recent whispers have again claimed that Apple is working on liquid cooled machines for release in the near future.