I would think you could buy a AM2+ board, proc and DDR2 pretty cheap whether it be used, refurbished or a cheap combo deal. 1080P isn’t going change like video games as far as graphics hardware goes. If it runs today then it should run several years from now. Unless the pockets are deep.
The only thing I would definitely change on my future main HTPC builds would be to use an ATX board. More options, e.g. more tuners, a 3d capable video card (if there needs to be such a thing), more sata ports (should it get moved to a server).
