Talking about the project, the project is finally on the npm registry and can be found here. You can get your hands dirty over it and the issue tracker is always there if you find things breaking and are ready to help.
I have invested a lot of time in writing tests, and here are the code coverage reports http://black-perl.in/mailman-cli/.
An experimental version of the API documentation is up and running here : http://black-perl.in/mailman-client-docs/.
To sum up, most of the implementation, testing and docs part is over. Currently working on better error propagation within the library and some minor features/patches.
Bye for now, stay in touch.