The Register has an interesting write-up about the Energy-Efficient Ethernet (EEE) Study Group and their findings for ethernet power management. It is estimated that Energy-Efficient Ethernet could save a total of $450 million every year in just the U.S. alone, with even more significant savings worldwide.

"We're going to look at ways to reduce power consumption by switching to lower speeds during periods of low link-utilisation," said EEE Chair Mike Bennett.