I'm guessing they haven't or it would have been mentioned but maybe they did and no one noticed yet. This is one thing that has driven me nuts about Sonar since I bought in. I would REALLY like smooth scrolling during playback (and lots of options to control how it behaves) because my old DAW had it and I guess I got spoiled. Such a simple thing but man do I ever miss it. I was told a while back it was not an option to save on system resources but I think our modern computers should be able to handle it. My old P3 XP system with 3gb of ram seem to handle it fine.
Also on a somewhat related note... is there a way to stop Sonar from defaulting to incremental scroll every time I boot up? I can't stand incremental scroll and because it's controlled by the ScrollLock key every time I boot up I have to remember to hit that key to disable it (which I always forget to do). Not a huge deal but inevitably I'll be zoomed way in trying to look at or edit something really intently, hit playback then completely lose where I'm at which results in a little brain smoldering.
Neither of those things are going to kill me though.