What a sysadmin's machine should be able to do
What a sysadmin's machine should be able to do has been on my mind recently, because my group is working on getting everyone upgraded from random creaky old hardware to modern PCs. (It's a somewhat contentious issue in many quarters, because it's not obvious to a lot of people that sysadmins need much more than a (graphical) terminal.)
At a high level, I feel that a sysadmin's machine should be able to burn DVDs, drive dual displays, and run fully virtualized operating systems at a decent speed. (Well, my actual wording to people here was 'run VMWare', but it's not the only choice for the job.)
(I'm assuming that everything has a basic level of capabilities, like USB and audio and gigabit Ethernet, so I'm only looking at uncommon things.)
At a slightly lower level, you want a 64-bit CPU so that you can run virtualized 64-bit OSes, because if your servers aren't already running 64-bit OSes now, they will be soon. In my opinion, it should be a dual-core CPU, so you can test genuine SMP issues, and it should have hardware virtualization, because that expands your options for what virtualization software you can use.
(Hopefully DVD burning is a no-brainer. Theoretically you can still save a few dollars per machine by buying CD-only hardware, but so many things don't fit on a single CD any more that it is more than worth the slight extra cost to avoid CD swapping hell. Especially on servers, where each swap may involve a trip to a machine room.)
As a recent convert to the church of the dual display, I would like to say that actually having dual displays should be mandatory. But I think that dual displays are still too often perceived as a luxury and the arguments for them aren't yet solid enough to overcome this, especially for sysadmins.
(I find the whole issue to be amusing from a suitable distance; I can remember back to the era when people paid quite large sums of money for decent 17" CRT monitors for sysadmins without blinking. Even ignoring inflation, two 19" LCD panels now cost less than one of those CRTs did and overall sysadmin workstations have become dirt cheap, so in a sense people are spending an inordinate amount of effort arguing about spare change. (The counter argument is that people spent so much money back then only because they didn't have a choice, and now they do.))