Heading of link is wrong: original source article says its 30 TIMES more efficient, not 30%. This would be a seriously big deal if it's actually commercialized: based on the Sandia video I have no doubt they have a working prototype.
Random fan on Newegg has ~2W power draw, so not much. But many processors are limited by heat dissipation, so better heat transfer could mean faster clock speeds (think water cooling, but much more convenient). Also means the fans could run much quieter (see the video), which makes sense since most of the fan's energy is going into noise/vibrations.