I've finally started working on Monticello 2, as part of the Google Summer of Code 2007.
Reading the source code of MC2, I found it well written and lots of unit-tests are presents. Colin and Avi are really good developers.
While reading, I refactored and cleaned the code. The resulting packages can be downloaded at http://www.squeaksource.com/Monticello2.
I've also updated the wiki page with links to documentation http://wiki.squeak.org/squeak/5624.
Playing a bit with the model interfaces, I didn't find a way to load a package previously saved in a file-based repository. It seems the method MDMemo>>getSnapshotFrom: is missing.
It's not clear whether Colin and Avi want to keep their "slicing" model. The "slicing" model is the possibility to store anything to a repository: a method, an instance variable, a class, a package... According to Avi, it seems it was a good idea, but it complicates things a lot. We will have to discuss about that particular problem.
What I plan to do in the following days is to continue reading and enhancing the source code, and find a way to load a slice from a repository.