Edit: I'm a moderator on the forums. I've been in touch.
I'm perfectly happy to get infrequent but stable evolutions for Sublime Text.
PS : However if the author could open his source code in order for me to take "inspiration from it" and improving my own Python codebase, that would be great :p
The thing is those "dev builds" are not actual releases -- the last 10 or so of them represent at most a few dozen commits, and quite small and isolated features or fixes.
So, to put it in other words, the activity is like he has abandoned coding again the last few months (after a short stint of activity that followed a year-long halt).
This is simply not true. Jon wrote a parser for the new .sublime-syntax files, rather than using .tmTheme files.
Since then, for 7 builds, it has been small scale fixes and minor improvements, even them stopping altogether around July 10.
http://www.sublimetext.com/3dev
I also remember what the development pace was like for ST2 -- those builds were coming up several times a week even, so that's something to compare against.