@prosodyim
As a demonstration, there is now an #XMPP channel that you can join from a traditional federated XMPP account, or from an #Yggdradsil #XMP2P setup, as described above: xmpp:[email protected]?join

If you're joining from an XMP2P setup, you'll still need to be able to make outbound connections to public IPv4 addresses; one day I may give the server a globally reachable non-Yggdrasil IPv6 address, but it will not be this day.

(The delay in making this announcement wasn't because setting up the server was particularly difficult; it was about as easy as anticipated above, but I've had other things to do.)