We do our work on the actual SourceForge CVS tree. We usually check in several changes a week, but often they are trivial changes that you are not likely to notice.
Josh and I will typically exchange an email or two about when we feel the time is ripe for a new major release. After a major release, there generally follow a series of minor bugfix releases, which Josh mainly manages.
I don’t think we’ve made a lot of substantial changes in the SourceForge CVS since the last major release.