Thats the frustrating part. The PC vendors were waiting on OS support, and due to the delays with Vista, it kept pushing the adoption out farther and farther. And now due to their hesitation, hard drive vendors can't sell their newest drives on the open market due to a very small UEFI install base. A PC from 2007 is perfectly capable of running Windows 7, but it's can't run a new 3TB hard drive as a boot device.

At work, it seems any of Dell's systems that come with the 5500 series Xeons can use UEFI. I'm curious to try booting Windows 7 on one to see how much of a difference it actually makes.