Long hardware maintenance cycles, especially in businesses.
The last 32-bit NetBurst (Pentium 4) systems with 2GB of RAM aren't that bad to work on, when given a video card that supports Windows 7/8 video features and a decently fast disk.
You don't need a whole lot more to run a greenscreen terminal emulator or a basic web browser.
I'm actually in the market for a old dumb box and for power(i.e. energy/electricity) reasons I'm shying away from the PressHot - Pentiums. I'm targeting a Core 2 Duo which seem like a great balance between power and performance and I'm reasonably sure that the money I'd save by going this route would not be recovered over the course of 5 years if I get a more recent box.
Unfortunately Win8 requires NX so only the very last ones will work and Intel released socket compatible 64-bit capable NetBurst CPUs not long afterwards.
Sure. I have a scanner that is now useless because Canon never released a 64-bit driver. (The useful lifetime of a scanner is longer than the life of an individual PC or the time a manufacturer will support it.)
Lots of scientific and industrial equipment will not have 64-bit drivers.
You could use it in a 32-bit VM. Since I went 64-bit, I've been using my Lide20 CanonScan though a 32-bit XP install in VirtualBox. Sure, the VM takes 20 seconds to boot to desktop, but that's better than junking a working piece of hardware simply because the manufacturer doesn't support it.