Do you mean slow acceleration and then moving at constant speed while pressing WASDRF? Free mode already works in this way. Acceleration/deceleration times can be adjusted in the 'user' config file.
I mean looking in a certain direction and being able to travel in that direction, as acceleration gradually increases at a certain rate.
I hope a sort of "rover" or car mode is added if collision could be made near perfect, sort of like Outerra. I can't imagine how fun it would be driving around on mountains on various planets/asteroids. cool
I second this... it may not be easy since the terrain would need to be fully generated by the time you reach it. I don't think it would be too big of a deal- land vehicles aren't fast and there would be plenty of time to generate terrain around the vehicle as it's moving- sort of like how FSX and other programs do. This would be really enjoyable on asteroids or very small planets- anywhere where you can get a good view!