I know one thing these boards could potentially be good for: emulating arcade games with a YM3812 or YMF262 using any SoundBlaster with a discrete YM3812 or YMF262 or a sound card from a competing manufacturer with a discrete YM3812 or YMF262. Old versions of MAME(pre v0.60) have support for sound cards with YM3812s or YMF262s and can actually use those sound chips to produce the FM Synthesis in games with YM3812s or YMF262s on the original arcade board. I don't know how well those motherboards would perform, but on the computer I set up for emulating games with a YM3812 or YMF262, MAME works beautifully with my SoundBlaster Pro 2.0 to produce FM Synthesis in the 3 games I put on the computer(Raiden, Zero Wing, Truxton).
The computer in question is running on a VIA VT82C693A chipset(and just so you know, everything has been overclocked since the FSB was brought up to the maximum 150MHz, and the computer's not complaining one bit - it performs very well with no slowdown in any games and no stability issues). What does that use? A proper ISA bus or the LPC bus through a PCI to ISA bridge? If it's the latter, then using old versions of MAME with support for real OPL2/OPL3 FM Synthesis chips along with an ISA sound card containing a discrete YM3812 or YMF262 will allow for the most accurate sound in games containing a YM3812 or YMF262 on the original board.
Maybe when I upgrade my main desktop computer, I'll purchase one of these motherboards and dual-boot DOS alongside Windows XP or Windows 7. Here's hoping there will be motherboards like this with support for the Core i7.