Might just be me but those great videos made with time lapse and camera movement are starting to all look alike.
Add the ability to do non-linear camera speed on that rail in the process and that'll be a nice feature.
Think like an engineer.
- pan-tilt ability too, also non-linear
- software that can help set up the shoot by automatically calculating the necessary movements, like pan-tilt and motion for precise tracking of sky or very close subjects. Could base it partly on GPS & compass direction data from tablet/cell phone. iOS/Android app to do all that and DL the data to hardware controller.
I'll add more if I think of it.