Megaflare, you have no idea what you're talking about.
2D fighters and 3D fighters are two very different animals due to strategy and style. The cellanimation style on a good 2D fighter is great fun to watch and play especially a lot of the Capcom franchises that are just a trip.
Some net play option would be nice so you're not limited to just your local friends and the computer. Maybe a very simplistic story mode for unlockables (extra characters, sets, etc. how well you do in each fight dictates what branch of the story you take) Maybe somebody new, like a Hunchback of Notre Dame freak like character with a rope swing attack and some kind of giant-bells schtick, or an ethereal more euorpean-styled ghost character with lots of flowing bits and ectoplasmic based attacks. Try to bring back as amany of the old characters as possible, but maybe not have all of them playable right off (have a few as unlockables).
Just some random thoughts off the top of my head. I used to play Rikuo, Jedah, and Hsien-Ko.