IBM has unveiled a new supercomputer line deemed Hydro-Cluster. The new machine essentially consists of a water-cooled Power6. IBM quotes energy consumption savings upwards of 40% and as well as 80% fewer chillers. The water cooling is done via copper plates attached to the top of each Power6 chip.
According to the article, IBM researchers are currently working on methods by which to pump water directly through the chip.
Not too many more details from the article, but there is a snazzy video. Check it out here.