I'd be interested in opinions as well. I'm not too excited to move on from 3 unless CS6 is something spectacular.
My "workhorse" has been Audition 2.0 which I bought about 10 days before 3.0 was introduced. I upgraded to CS5.5 just to keep my ability to upgrade route alive. For the things I do, CS5.5 is more or less useless as so many things I do did not come across to that version. I do a lot of editing of lectures and sermons. I think the "engine" in CS5.5 and now 6 is improved considerable when it comes to processes like noise reduction. I will open the raw recording is CS5.5, run Noise Reduction, save the file, and then return to AA 2.0 to actually do the tedious editing. With me, the problem is the user interface rather than the "features". In 2.0 I can include the items I use regularly on the TOOLBAR and then create some favorites on a PANEL that is constantly available for a simple mouse-click. With CS5.5 and 6.0, the whole User Interface has changed from "constantly visible mouse-click" availabilities, to either two to four mouse clicks through menus, or learning the gosh-awful keystroke combinations. Since I do this part time, I think in 5 or 6 years I may be able to finally commit the key stroke combinations to memory.
For people doing other kinds of editing and production, the features you need may be more available, more intuitive.
Every once in awhile I pull up the old Cool Edit 2000 (NOT Cool Edit PRO) and open a raw file and do a few things like noise reduction to remind myself why putting up with what is for me an awkward User Interface is worth the hassle. Adobe has certainly re-invented the underlying engine and made it SUPER in comparison.
For those of us with a few age wrinkles marring our faces, the abandonment of the old Classic Windows style for the new floating panels and ribbons is a harsh and cruel mandatory adjustment.