We have a Subversion repository that is not going to move to git in the short to medium term, but I would like to use a DVCS for controlling and versioning 3rd party libraries.
Is there a way of using something like svn:externals to fetch/link a revision from git, driven by the Subversion checkout?
There is no direct way to do this, since svn:externals are restricted to subversion repositories. You might use github for the git repositories, since github has read+write support for svn.