Igor,
4.6 _is_ the maintenance release for 4.5. There's no rule saying that we must release maintenance releases as another dot.
4.7 will be the release which will have more significant modifications to the core.
It's true that 3.2 has had "production" status for longer than 4.x, but it still had some pretty horrible bugs that were uncovered and had to be fixed.
The degree of production-readiness varies a lot throughout several parts of 3.2. 4.5 however, is in much better shape, and 4.6 much more so. You have to realize that the release standards that OpenACS goes through are in average much higher than those that ArsDigita used, judging by some of the code that was released.
4.x simply offers so much more in terms of ease and consistency of development, with so much more real-production-ready code that it's hard for me to find time to even go back to 3.2 series to work on its maintenance. Much less want to develop a new site with it.
