Yes, by a lot.
The GTX 280 can pull almost as much as 2 8800gtx cards.
EDIT: My bad, I think I was thinking about 2 9800GTX cards. It looks like it pulls around 25W more than an 8800GTX does.
And according to pcper, an ultra pulls like 30W more than a GTX does... So apparently they are very close even though the GTX 280 uses an 8 pin and a 6 pin power connector.