git-svn works directly on the live svn repository. (so does git-cvsimport) it works bidirectional, that is, after importing it can then push commits back into the svn repository. (there is also a git-cvs-exportcommit tool which can commit to cvs, have not tried that yet though. being able to commit back to cvs/svn is one of the goals however, so that i (and anyone else who likes) may use git locally regardless of what the main repository is running)
Excellent! Exactly what I was hoping for.