So after seven years of loyal service, I'm finally retiring my old CPU and motherboard, because the CPU keeps overheating and I can't be bothered to fix/replace it, since the mobo is socket AM2 and who even makes that any more?
For now I'm getting an mITX board with on-board processor. Nothing fancy, dual core 1 GHz, but I mainly use this computer for media, browsing, etc, it's just hooked up to my TV. Eventually I'll probably get a new ATX mobo and processor so that I'm actually putting my huge ATX case to good use as a workstation or something, but for now I didn't want to spend hundreds of dollars on a fix for a computer that I wasn't using for any intense tasks.
On the plus side, if I do decide to re-upgrade, I can use the mITX board for a side project. Maybe I'll gut a NES case and build myself a little media player box inside that. I gotta say, the small form-factor desktops really appeal to me and they're fun to build, but if I wanted to do something like CAD or CFD where I'd like, say, a hex-core processor, there's really no good mobo options in mITX form. Hopefully there will be some good AM3 socket options soon.