On the other hand, lots of small projects don't have mailing lists, and might not want them. The enhanced pull request feature allows a smaller community to ha

On the other hand, lots of small projects don't have mailing lists, and might not want them. The enhanced pull request feature allows a smaller community to have a good discussion about a new feature, without having to maintain a mailing list. I think the real solution here is for Github to add a feature where pull request notifications can be sent to arbitrary email adresses (though you can probably hack around this today). This way, if the project does have a mailing list, and prefers to discuss pull requests there, then the mailing list is not out of the loop.