For me I want the DAW to be my partner in the studio, for me the biggest things that gets in the way of creativity is what I call the editing barrier. So my suggestions would be, and these are pie in the sky in some ways.
Fluid tempo detection, when I start playing around with something, I don't necessarily want the tempo locked in. In my ideal world I would noodle around and as I played the tempo would follow me in real time I could push and pull the tempo in the same way a drummer would follow me if I slowed or sped up, failing this allowing tempo to be control by a midi expression pedal within a user definable range would be awesome so I could tweak tempo as I went.
Voice control of editing and comping. I want to be able to shout out, quantize 8 bars of take 3, loop, put on new track and duplicate x4 please. Then take 8 bars of take 5 quantize loop and put in same track as duplicate x2 for chorus.
Sonar does it, and then I can straight away record another part of this new structure, I have not had to move from where I am sitting or put my instruement down and I am back creating.
For me this would be the ultimate in ease of use. As it is I noodle away building up issues in the take, then I am faced with an hour long editing session to clean up and bring order to the chaos before I can carry on building, and often the inspiration is lost.
So basically I want a virtual tape engineer or editor please.