Not sure if this was posted earlier, but this would be really awesomelly useful.
One could construct beats, and loops…
…and then preview them later on (so that they would be played back), and load them (if preferred) into songs.
This could also include VST settings, such as VSTiplugin data, and the FX settings on channel to make it even more perfect.
I guess something along these lines has been proposed earlier - but what would be really awesome, is that the sample and note data on the saved tracks including the FX settings would get saved.