- Improve physics (skidding, pushing other karts aside)
- Career mode and/or different difficulties for challenges
- Eye candy (light effects, light maps, normal maps)
- Game replay
- Ghost races
- Reverse tracks
- Online highscore lists
Only some of this will be ready for 0.8, while others will come in subsequent "minor" releases. Also, a release might be done even if not all the features are met, while other times features might come in earlier than anticipated. So these are the main goals, but they are not 100% set in stone: other things might be added, or some of this might get postponed.
Some of this are already in the works. Improved physics is the most important feature for 0.8, and hiker has already started on it. Meanwhile, Auria has added normal map support, so for track makers this is a feature to consider.
We do not know when we will be ready for a release, but as a rough, unfounded guesstimate, maybe we'll see the 0.8 release 6-12 months from now on, give or take a few decades. ;)
What we do know, is that we'd love to see more people join in on this project in any area they are interested in. So if you want to help out with your skills, please get in touch and we'll try to get you started. :)