I've created a list specifically for discussing Mailman 3 design and development. Feel free to subscribe at:
I'd like to keep MM3 discussions off the main mailman-developers list as much as possible. The list will be open and will be run with essentially the same policies as mailman-developers and mailman-users, except that it will reject posts by non-members. Sorry, but I think this will help keep the signal to noise ratio high and it reduces my administrative burden.
I want to give the list a few days to get populated and then I'll start posting some issues in preparation for the upcoming sprint at Pycon.