I think that the looper should be improved.
A nice issue: If you record a loop with eg 4 bars, it should be possible to play only the by mouse or midi devices buttons (midi notes) selected pieces on the one hand with free space (silence time for unselected pieces) and on the other hand there should be no free space (skip the unselected pieces of the looped material). This would be a great feature for IDM stuff and indeed is usable like an inbuilt stepsequencer.
Another nice issue: Very, very fine it would be if you can set (by mouse or MIDI CC) the beginning and the end point of the loop. Ansolutely killer feature. Maybe in two options (like in delay effect used): First is with grid; Second is free (Samples).
Btw: What about a better timestretching AND pitchshifting?
Share your wishes for the future of Ableton Live