I just restored my svn server at home this weekend--apparently after rebuilding my HTPC a couple months ago I forgot to restore my personal svn server--and after checking in my own bits, I also checked out some SourceForge code bits using TortoiseSVN. So then I was looking for TortoiseSVN-like Explorer integration of Team Foundation Server so I could do some source code check-outs from CodePlex.
I found an open souce upstart called "Turtle" whose name was apparently so controversial that it seemed to have been buried in its name's confusion. Then I found DubbleBock, and from there I found LizardTF. This is something to watch.
http://www.codeplex.com/lizardtf