We have a new installer project in development, which we hope to release in 1.17. It includes a feature which encourages users to sign up for our release announcements mailing list. But maybe we need to do more. Should we take a leaf from WordPress's book, and nag administrators with a prominent notice when they are not using the latest version? Such a feature would require MediaWiki to "dial home", which is controversial in our developer community.
If MediaWiki dials home, it should be configurable in such a way that it can be turned off. There are instances in use in places that would prefer not to their presence known. Enterprise use in general fits this category.
Respectfully,
Ryan Lane