that only makes sense for cvs.
in svn branches are directories anyways, so there is no difference,
and in git copying using different repos would not gain you anything, and only waste a lot of diskspace. everyone gets a copy of the whole repo anyways, and since the changesets in both repos would be identical up to the branchpoint, i could create a merged repo by just fetching from all individual repos, but you could just as well fetch each branch into a seperate repo (and waste your diskspace with that)
btw: i am running git-svn now since yesterday, and it seems to be about halfway through. i noticed that cvs2svn creates some wierd commits to mark tags, which messes up git-svn because that now creates a branch for each tag. this makes the tags less useful in git. i don't know if that is a sideeffect of cvs2svn or git-svn though.
greetings, martin.