>> Awesome!
>>
>>> I remember hearing something about a bit of good refactoring  
>>> recently
>>> that permitted *switching out the sources implementation* for an  
>>> image.
>>> Perhaps it could be backed onto a Git repository using this code.
>>> Methods would then know the sha1 of the blob that holds the source.

This problem is a real tester for the process we use because it is so  
easy to break the image completely.

I posted some discussions that might interest you here, and I have  
completed phase 1.
feel free to comment/join the discussion here.

http://smalltalkers.pbworks.com/System-Sources

regards

Keith

p.s.

I just posted some brief highlights of the decision making involved  
between bzr,  git and mercurial.

http://smalltalkers.pbworks.com/Why-Bazaar