@codinghorror Is your caution limited to the embedded implementation? I ask because we are just about to go into a testing phase prior to - hopefully - moving to Discourse.
Currently all of our network members are using a listserve - which serves the needs of many in our specialize audience. In any case, mailing list mode is how we will have to start in the new environment. From there, how members decide to use Discourse will be up to them after that. Nevertheless, I can imagine a significant number of users may prefer to stay with an email mode.