The new version of MediaWiki will hopefully be on test wikis and MediaWiki.org from 20 September. It will be on non-Wikipedia wikis and some Wikipedias from 21 September. It will be on all wikis from 22 September (calendar). This is the version that was meant to go out last week.
You can join the next meeting with the VisualEditor team. During the meeting, you can tell developers which bugs you think are the most important. The meeting will be on 20 September at 19:00 (UTC). See how to join.