I want to see the GUI slightly reworked, to be very slick and sleek... I'd like to see some really interesting graphical things down. I really like the workflow. I like, "the skylight, and like the inspector, and I love the way the prochannel works, and all that stuff."
What I don't like is the very limited color things that we can do, and these very, "boxy," shapes. Sonar is basically, "a corvette," in terms of its abilities. Now it really needs to start to look like one. Studio One and Digital Performer are really kicking butt here, so Cakewalk should step it up.
All that said.. I'm excited to see X3, I'd like to see what the bakers do with it, and hopefully we can really spruce up the look and feel a bit more. Software should be pretty too!! and IMHO, "gunmetal gray," is so drab. Really, when I use Sonar, I feel like I am in a submarine from the 1980s. But I should feel like I am on a spaceship from the 2230s.