In my experience, major upgrades to BiaB most often get released in December, in time for the XMAS season and/or he beginning of the next New Year.

Less often are releases with the ".5" appended to them, in the middle of a year.

While neither are ever announced by the company ahead of time, I've found that you can pretty much count on the December release to happen every time. Does not always happen with the half-year cycle, though, that's the exception rather than the rule.

--Mac