Eric,
I'm interested in doing the same. The 2010 extension is located at
https://github.com/vsClojure/vsClojure by Jon (jmis). However, it hasn't seen many updates recently. The last official binary was a year ago. He has a refactoring branch which his last commit was 3 months ago.
I made a fork of the main branch at https://github.com/speige/vsClojure where I'm trying to add 2012 support & fix some of the previous bugs that have been reported. If I make any progress, I'll ask Jon to merge it into the main branch. I did upload the 2012 extension to the visual studio gallery, so you can download it and try it out, but I can guarantee it doesn't work well as I've just started to work on this.
If you'd like to contribute, I'm happy to give you access to my GitHub fork.
Devin