It's an interesting thought Mr Hyde, and I think you're right to say that there's really no basis for comparison right now.
I personally think the industry would be much better served at this point to focus on accuracy before and after the actual recording itself. What I mean is that even if you were able to hone the CD format to the point where it was 100% accurate guarenteed, you'd still be using instruments and processors that are much less than 100% accurate, as well as having the vast majority of users listening with sound reproduction gear that's also much less than 100% accurate.
So, I guess my point is that unless you made improvements on both sides and had the commitment from producers and listeners to actually purchase and use such gear properly (in accoustically perfect environments), there probably wouldn't be much point to increasing the accuracy of CD recording much. It wouldn't serve an artist's purposes much if he/she were able to take advantage of a higher bit-rate to preserve that wonderful, subtle bit of "airyness" in thier reverb in a particular passage only to have the listener fire it into thier mid-line CD player on thier mid-line stereo system with mid-line speakers and play it in thier less than acoustically perfect living room. :zombie: