Hi! Aside from the remarks made by others (and speaking as someone who maintains Python software), there is one reason for me to not switch Python 3 to stable yet: lack of compatibility. Software that runs with 3.x will not run with any 2.x version as of today (and I doubt there will ever be a 2.x version of Python that can run 3.x code).
As such, upstream devs will have to maintain two branches of software for a rather long time. Thing is, some projects just don't have the manpower to maintain two branches, so they will stay with 2.x versions for now. Yes, it's a catch-22, but I doubt that a sufficiently large portion of projects will have a 3.x-compatible branch/version this year (sufficient meaning over 95%). On the other hand, we can patch everything that doesn't run with 3.x (i.e. "fixing" the shebang lines and maybe assorted paths). The Python team is more suited to evaluate the feasibility of that. Regards, Tobias PS: As an illustration: just look at how long it took to get a 2.6-compatible version of mailman into the tree...