Really "simple" rules to help ease into that late majority curve they can't seem to reach.
Ah! That explains the cruft I've seen today with the mess of truncated tweets with links to themselves (twitter.com/i/web/status/…) at the end of the tweet text. (If you use a third-party client, you'll see this duct-tape in the tweets.)
The TechCrunch article is a much better overview, and outlines all of the rules associated with the change. This is just a simple tweet saying changes have been rolled out.