The Serial ATA International Organization (SATA-IO) has announced that it is working on a new specification that will provide power to external SATA (eSATA) devices without the need for a separate power connection. Called "Power Over eSATA initiative", the specification is expected to be completed sometime in the second half of this year.
Devices taking advantage of the new spec no longer will require a separate power cable but will draw power for a single drive directly from the host system using the Power Over eSATA cable. The SATA-IO said that the new cable will remain compatible with the existing eSATA connector and support the current maximum interface transfer rate of 3Gb/s. Power Over eSATA products are expected to be available on the market as soon as the second half of 2008.
News source: Toms Hardware