You can help write the next newsletter: whenever you see information about Wikimedia technology that you think should be distributed more broadly, you can add it to the next newsletter at <https://meta.wikimedia.org/wiki/Tech/News/Next>.
The RevisionSlider user interface has changed. You can now select revisions by clicking on the bars. You can move the blue knob past the yellow one and the yellow one will move along, and the other way around. 
Some users have problems loading very large watchlists. It is working better than earlier but the problem has not been solved. The developers are working on fixing it. Until it has been fixed you can turn on "Expand watchlist to show all changes, not just the most recent" in your preferences and see if it helps. 
The new version of MediaWiki will be on test wikis and MediaWiki.org from 5 September. It will be on non-Wikipedia wikis and some Wikipedias from 6 September. It will be on all wikis from 7 September (calendar).
You can join the next meeting with the Editing team. During the meeting, you can tell developers which bugs you think are the most important. The meeting will be on 5 September at 19:00 (UTC). See how to join.