Subversion
Have been looking at the Subversion 1.1 release candidate, and it looks pretty good. This could be the point where more people start to seriously look at using Subversion as a CVS replacement.
This would be largely due to the new fsfs repository backend. This new backend doesn't use berkeley db, and shouldn't ever wedge like the BDB backend does occasionally. Furthermore, you don't need write access to the repository to perform read only operations. This should make it a lot easier to set up systems where you have multiple ways of accessing the repository (eg. svnserve/ssh for write access, DAV and viewcvs for read access).
The fsfs backend stores each revision of the repository as two files in the repository (one for changes to the files/properties, and one to store revision properties), and doesn't modify the files associated with previous revisions when performing a commit. This means that the the existing backup and mirror infrastructure that projects have set up for CVS repositories should work equally well for Subversion.
The "new file for each revision" policy also has some nice features. In the case of svn+ssh access where each committer can directly access the repository files, it means that the existing revisions in the repository can be made readonly without preventing people from committing new revisions (something that can't really be done with CVS).
These administrative improvements should make it a lot easier to deploy Subversion, which in turn let more developers take advantage of its features.