Well, got some new deets on the HTPC idea, so if someone wants to chime in I'd appreciate it.
I began looking around for some different scenarios. Pretty much any route I went I'd be paying 300 minimal, which was stinging a little bit. The current Sandy Bridge lineup, while solid, seems to have a 24fps bug issue that is more noticable than some other platforms out there. Since the new 2012 Ivy's are coming by Intel and are to fix that, I had trouble justifying 300+ on a HTPC setup when their next product should fix that issue.
As a result, I was semi back to square one, but I kept looking at the parts I had laying around. I ended up finding a board by ASRock that is AM2/AM2+/AM3. Coupled with that, it has a PCIE X16 2.0 slot, so if the onboard graphics (ATI HD 4250) doesn't hold up to par with 1080 playback, I can easily drop in an updated graphics card and be rolling. Considering this board supports up to AM3 I can also get a higher powered proc in there if need be as well, though I doubt that'll have to happen.
Nonetheless, 60 bucks and I can get a new board, with enough older compatibility to use my DDR2 ram and AM2 processor, and enough newer compatibility to handle a dedicated updated graphics card as well as a semi updated processor if need be. 60 sounds a lot better than 300... so I think I may go this route, especially considering my buddy has a similar build (but with an HD 3200 instead of HD 4250) and claims he had decent 1080 playback in Linux.