i dont know, i've always seen 7+ string guitars as a great idea in theory, but then whenever i get around to playing one its like "meh, this isnt so great afterall"
give it time, the 8 strings are going to obviously be a niche market, if somebody besides vai can use the 8 to its full potential and not just mindless wanking (im looking at you cooley) it going to be awesome, if not, dah well