Continuing the discussion from Only Gravatar images:
While we have now enabled support for uploading avatars, new users still have to go through the effort of uploading their profile picture if they don’t have a Gravatar account, and existing users still need to remember to go to Discourse when they want to change theirs.
We should add Mozillians in much the same way that Gravatar is currently supported, and make it the default for new users (provided they have a public profile pic on mozilians, or a mozillians account):