MediaWiki and WMF?
Fragment of a discussion from Project:Support desk
According to the roadmap 1.17 is "very nearly complete". Release should be soon, I hope.
It's probably okay to use the 1.17 beta and then upgrade when the official release is made available. It's hard to be certain though; there could still be unforeseen problems. While 1.17 works fine for Wikimedia, it is quite a different environment than what you'll be running. There are still some issues with the new installer, but most of them are minor.
