Features that have already been announced: Roster updates, updated AI (borrowing from the Fight Night series), tag mode, team fire and a new online campaign mode called Road Trip. (More details can be found here.)
Some things I'd like to see:
- Button power-up codes, adding the ability to dunk from anywhere, have permanent fire, etc. They're something you'd want to disable for online mode but they're kind of fun, if you're playing against a friend in the same room you can agree whether or not to use them and if you don't want to ever use them when you play, just ignore them.
- You could also (or alternatively) have the same abilities such as dunking from anywhere on the court included legitimately as power-ups, perhaps in Remix Mode or as an option for regular gameplay (similar to the option in NBA Jam: Tournament Edition). Another TE feature I wouldn't mind seeing is Hotspots, which appeared on the floor at random and gave players an opportunity to score up to nine points if they made a shot while standing on one.
- Old School Tournament Mode, where you play each NBA team in succession and can select a different team for every game if desired. In other words, the format that was used in the original games.
- Create-a-Player. There's a fair amount of cool stuff you could do with this but even a fairly simple CAP feature would be nice.
- Something similar to the Quick Picks option in recent NBA Live games, essentially a de facto custom team feature where you choose a team and can assemble a fantasy squad. A fully fledged custom team feature would be even better (it wouldn't have to be too in-depth for a game like Jam to still be fun, in my opinion) but the quick picks approach would be a suitable alternative.
- Ability to edit rosters. Maybe this could be in the form of downloadable content post-release, similar to what THQ did in releasing an attribute editor for Smackdown vs RAW 2011 but if it's in the game to begin with, so much the better. I guess unsuitable ratings is going to be less of an issue with the roster updates but since there'll still be disagreements it would be handy to have. Online play would of course be restricted to the latest official roster.
- More stable online play. An absolute must.
- Ability to capture videos and screenshots, compile highlight reels and upload them. Perhaps not as much call for it as with the sim titles but it could still be fun.
- Custom controller configurations. I also wouldn't mind an old school control scheme where a shove is executed by pressing steal while holding turbo.