Things have been quiet at MusicBrainz in the past few weeks, but don’t let this fool you! We’ve been working hard on getting the schema change release put together. We’re on schedule for releasing this tomorrow at 13:00 UTC, 15 May, 2013.
We’re going to start the release process at 1300UTC, but the site may not go down just yet then. We’ll get started once we have all of our ducks in a row — to get more updates from us before we start, please follow @musicbrainz on Twitter or join us in IRC at #musicbrainz on irc.freenode.net.
Thanks, and wish us luck for a smooth schema change tomorrow!
MetaBrainz Blog 
What changes will be taking place and will they be included in the database download?
The list of changes is mostly the same as originally stated (http://blog.musicbrainz.org/?p=1826). MBS-3978 won’t be happening yet, and a few others will be only in the schema but not in the site UI for now.
Changes to the database will, reasonably enough, be included in the database – an upgrade script to get to the new schema so that new dumps and replication can work will be posted.