The new version of MediaWiki will be on test wikis and MediaWiki.org from November 8th. It will be on non-Wikipedia wikis and some Wikipedias from November 9th. It will be on all wikis from November 10th (calendar).
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 8 November 2016 at 20:00 (UTC). See how to join.
You can join the next meeting with the Architecture committee. The topics this week are Image Thumbnail API and allow SVG files uploaded on MediaWiki to have XHTML namespaces. The meeting will be on 9 November at 21:00 (UTC). See how to join.
RevisionSlider will be enabled by default on all beta wikis, on testwiki, testwiki2, mediawikiwiki and de.wikipedia.org.