2009/6/5 Roan Kattouw roan.kattouw@gmail.com:
There aren't two different policies. When enabling a new extension, the latest version from SVN is installed (provided it has passed review), and extensions are updated together with the core MediaWiki code. Once upon a time, we had sort-of-weekly code updates, but right now Wikipedia is running code dated March 25th.
We're planning to hire a full-time QA engineer in 09-10 to help with code review, bug triaging and deployment - that should help get us back to a more reasonable schedule.