I don't know about the new alu version, but the last gen white keyboard uses AA batteries and has no USB port. The batteries seem to last long (similar to a remote -- each keystroke has less juice than say your TV remote. Of course, you probably don't push your TV remote buttons 80 time/minute either). I'm still on my second set of batteries after 6 months, but don't use mine much -- actually are interested in it, PM me. The mouse seems to use batteries quicker, but then again I used it more... duh. (oh, and I'm keeping the mouse!)
Additionally, if you're looking at the new alu version, be sure to try it out. I did and didn't like the laptop key feel of them. I'm use to conventional keys. They do look cool however.