we have a computer lab full of mixed machines and different subversion client versions (most of them with 1.6, but also a few where we need 1.7)
currently we can't set a different workspace version. Our build-tools use internally the host subversion client. Because of the incompatibility between 1.6 and 1.7, those tools can't read the 1.6 format without upgrade, and jenkins can't read the 1.7 format if we do so.
a really nice feature would be if we could set the subversion workspace format/version for each jenkins-slave.