I think that the program's usability would benefit just with a little bit of reorganization of its Menu and Options system. Yesterday, for example, I was looking the way for generationg scales over a chord progession, a new feature from v2011 that I've never tried until now. It took me about 15 minutes finding the way to do it, because it was just not obvious for me that such a feature would be under "Soloist" menu, and because the help file explained how that feature works, but not where it is. Then, I remember the first time I tried to assing a VST synth to a MIDi track, It took me some time discovering that such a feature wasn't present on the track right button-menu, but trough an icon that was hidden by default (or, even less intuitive, under "Option -> MIDI / Audio Driver Setup -> VST/DXi Synth Settings). An now, after several years working with the program I'm just looking the way to hide the piano on the main screen

Another key could be simplification. I don't understand, for example, why having so many different picker windows and filters for doing a thing that is essentially the same: choosing the right tracks for your song. Try to explaining a newcomer (who, remember, just want the right track for his song) the difference between Realtracks, Realdrums, MIDI Styles, RealStyles, MIDI TRacks and Loops (and where are their different picker windows), and he'll probably will get crazy. In my opinion, if all Realtracks, Realdrums, Realstyles, MIDI Styles, MIDI tracks and Loops could be choosen from a single Picker Window the workflow would be greatly improved, specially in this critical area, where having so many styles requires a simple and effective search system.
Alowing the customization of the menu system and other elements of the GUI would be great too.