This is a list of things that should be done:
. Implement a ServerSession (sibling of ComponentSession and ClientSession) that will be responsible for establishing the connection and authentication. First version will use Server Dialback and not SASL. See: rfc3920 - 8. Server Dialback
. Change the routing of IQ, Presence and Messages to consider foreign domains. Some work has been done in this area but still is incomplete. See: rfc3920 - 10.2 Foreign Domain
. Implement presence probes. See: rfc3921 - 220.127.116.11 Presence Probes
. Implement handling of presence subscriptions. See: rfc3921 - 9. Subscription States
Right now nobody is implementing these changes but many things have been done when we added support for components. My estimation is that in order to finish these changes approximately 3 weeks will be required.