I'd rather that a major release number signify some major, breaking change. But, I don't think that's realistic on something as broad and mature as NB is. At the same time I wouldn't want all of the old modules to break on a ".2" release, but it's hard to envision any real scenario where that could happen.
So, a quarterly dot release with an annual version change seems fine by me. I see no reason to not stay with the current scheme, and release 10.0 next year a quarter after 9.3. I think jumping to 18.1 or 19.0 to keep with the calendar doesn't buy anyone anything. I'm not sure if point releases after that are really important (9.2.1). Those should be manageable via the update process, right? without a formal release? or is there no way to update the core via the update process, but only modules?
