I run an Apple Training Centre and am a pro musician. While I agree that Logic is feature rich and pretty stable, it is not attractive to new users. Its inconsistent UI (plenty is unchanged from Atari days), complexity for straightforward tasks and over-reliance on the Environment as its main architectural tool mean that there are design compromises and the hundreds of students that go through our studies find other software easier to learn and easier to use.
Logic's business case will be energised not by the thousands of us experienced users but by the hundreds of thousands of new users still to come to the fold. That's why a major redesign is needed and that means the kind of revision that Apple bravely did with FCP. Sure, they released it too soon but it's now a fantastic product and the release notes give the indication of a vibrant product with masses of ideas in the pipeline. http://support.apple.com/kb/HT4589
I'd love to see that kind of vibrancy in Logic's release notes in the next two years. And, if the transition upsets a few users, let them (and me) use the current Logic until Apple can establish a stable, feature-full Logic X with the right architecture and jettison legacy code and legacy designs.
Trouble is, while the design of ES2 is really dated, it's a good synth but is totally put to shame by Sculpture. So what to do with those fab but archaic interfaces? Can't see Jonny Ive putting his mind to those in the near future...