Just to sensationalize this thing a bit, here's the part where the creator of Guilty Gear, Daisuke Ishiwatari, gets a little raw:
DI: We don't really have a sense of how popular fighting games are in the states, so it's tough to know how much demand there would be for accurate online fighting. We know the FPS is king there, and also that Soulcalibur, which I personally think is junk, has a big following.
Word. Be sure to check out the full interview.