I'll jump in and say I'd love to see Hirohiko Araki! Like blind51de said there's new anime coming out, also: they just rereleased the old Jojo dreamcast game on XBLA, and there's a new Jojo game coming out next year (dunno if in time to make a tournament at fanime).
(this would also basically guarantee that the dealers would have some jojo artbooks for sale!)
I also second the Hiro Mashima request.
Also, I don't know what sort of stuff the staff does to entice mangaka to come to Fanime, but I'm sure some of them (i.e. Kenichi Sonoda) would like to go shooting...(maybe even break Shirow out of his shell? probably not, but that's the first time I've heard that he's a recluse)
(this would also basically guarantee that the dealers would have some jojo artbooks for sale!)
I also second the Hiro Mashima request.
Also, I don't know what sort of stuff the staff does to entice mangaka to come to Fanime, but I'm sure some of them (i.e. Kenichi Sonoda) would like to go shooting...(maybe even break Shirow out of his shell? probably not, but that's the first time I've heard that he's a recluse)