There seems to be a lot of confusion over just what the RELENG_1 tag in CVS means.
We’re taking a similar approach as the FreeBSD project in our CVS tagging. Commits now are all made to HEAD, which is developer-use-only now. After a certain period, these changes are MFC’ed into the tag RELENG_1. MFC is Merged From -CURRENT. HEAD in CVS is basically like FreeBSD’s -CURRENT, though generally we don’t refer to it as such. We use the same term, MFC, because that’s what we’re used to.
All public releases from this point on will be made from RELENG_1. This will eventually help us stabilize releases without slowing development, as known-unstable code and features will remain in HEAD.
This doesn’t mean much of anything at this point other than we’re getting closer to the first beta! FreeBSD 6.0 RC1 is out and is likely to be the only RC. 6.0 release is expected within a couple weeks or so. We should hit beta shortly after that, but no promises.