1 drawbrack i can see is that it has onboard video, or at least thats how it sounds to me. Also no mention of an AGP slot. Granted you could later add a pci video card. Its powerfull enough for mame, no question. Just comes down to whether or not you'd need S-video or other add-ons since your limited to one PCI slot. Not sure this would be a first choice for a mame cabinet, but it could suffice.
-Kevin