Now that Sam has announced the 1.18 Release Candidate, we'd like to make sure that we've created a tarball that will work.
Please give 1.18RC1 a try and add your experience to http://www.mediawiki.org/wiki/MediaWiki_roadmap/1.18/Upgrade_reports.
I just upgraded one of the wikis I maintain from 1.15 and recorded my experience. Of course, as Sam writes in his announcement, you should probably not do this on a production wiki "unless you are both very brave and very confident in your MediaWiki administration skills." So, maybe you'll want to try it in a test installation.
That said, let us know of your successes!
Of course, we'd like to know about failures, too, and that page is an appropriate place to report them (in addition to bugzilla), but we really need to know if this release is as good as we think it is.
Thanks,
Mark.