I'm curious how DOA will progress without Itagaki at the helm. It would be nice to have another 3D fighter that offers a comparable amount of depth as Tekken and Virtua Fighter.
DOA has quite a few awesome characters I always liked, mainly Lei-Fang, Baymen, and Jann Lee. That drunken fist user from one of the recent titles looks kinda cool too, he reminds me of the dude from Double Dragon on Neo-Geo that also used drunken fist.
I think some more fighting style diversity would be good... my top picks of course being boxing, taekwondo, and capoeira.