I think Audition was left out of the CS because it is strictly a windows app and porting applications to different systems can take a lot of time. It's tons of work to port an application as large as Audition and then even more work to manage the different ports in a single application project. I'm sure Adobe wouldn't release anything until it was 100% or at least 99.99% complete and working smoothly... So if there is a Mac version coming out then it's just a waiting game as the Mac port will need to catch up to each new release for windows...
In other words "It's complicated." But I'm sure Adobe would never actually confirm nor deny that any such application is or is not in production. They're kind of crazy like that
I'm sure they could use some Mac beta testers if Audition ever does get a Mac version, but I wouldn't annoy them with more questions unless they actually announced that they were looking...
I'm not sure about that percents...
For example a lot of Premiere Pro filters are not included in Mac version.
They never explained why these filters are missing, nor confirmed that they are working on it.
Soundbooth is just a limited version of Audition as far as I can figure, perhaps Adobe's prolonged attempt to port Audition to Mac format software. When/if they get Soundbooth up to the same level will Audition/Soundbooth become, essentially, one product? Although I also work on a MacBook Pro, Soundbooth held no interest for me because it didn't do much compared to everything I already have. I was working a lot with Audition but have now moved on to Logic Pro (MBP) and Sonar (PC) and Melodyne Studio (both) as Audition appeared to have reached it's end of life point (until they get it transformed?). Too bad, I used it from before Adobe bought the company... still use it on occasion. Not that anyone will be needing my input but thought I'd write anyway. Too little too late for any significant share in the marketplace except as part of a suite where it will always be limited in what it can do. So, it seems to me, that Audition will quietly fade away.... too bad. As long as they continue to sell Audition 3 Adobe will never admit it's over, just that the same team continues to work on both products (only true if they are transitioning Audition into Soundbooth).