Send marked up messages that look good in both HTML and can be transformed into threaded comment strings in your client. Embed XMPP chat, and set up enabled-by-default encryption around the whole thing. Leverage mailing lists for your special interest groups and your public pages. Sell server time for managing the mailing lists and image hosting, and for a web client.
The infrastructure is there, just forgotten.
This has been banging around in my head for a few years now, but I'll never have the time to do it myself. If you can poke holes in the core concept - please do. It needs to be fleshed out.