The new debian-powered server I'm building is coming out great!
It has a high powered CPU, a serious motherboard, a low-power graphics card, a dual gig-E network PCI-X card, plus 2 gig-E on-board nics, a SATA RAID card, and four 250GB hard drives.
The power supply is an "80 plus" rated device, so that's good, too.
How much power does all this use? Around 160 watts it looks like so far. I'm sure I'll be able to tune that down using ACPI, but I'm pretty happy even with that.
Considering that with most of my computers I try to keep the power consumption under 40 watts, this might seem way too high. But keep in mind this is a high-performance server. This is one of the first servers I've measured, but I think for the most part, they use a much higher magnitude of power than desktop computers and workstations.
I'll be sure to post more information as it becomes available. UPDATE: Wiki page on the Xeon L5410.