Would be great if users could map out their keyboard to commands - and even the possibility for them to map them for executing scripts. 

Rotating the selected objects for example, could not only be mapped to "R" or "Spacebar" (or whatever), but also have the rotation amount per-configurable too. Or perhaps, the user might have created a "Rotation" script, so by pressing "R"/"Spacebar"  the script will execute.