Subversion 1.0 was released today, so that's one reason less to stay with CVS.
The 2 candidates I'm considering for future projects are GNU Arch and Subversion. Arch's command set seems a lot more complicated, and documentation is lacking, but the feature set is quite impressing. Subversion looks very familiar if you know CVS, but the one thing I dislike is using Berkeley DB as backend instead of the file system. Not that I think it's unstable, but being a pragmatic programmer, I prefer plain text files over any other storage format.