A mailing list dealing with P2PSIP and discussing issues related to it, development for it, and research into it, has been set up. You can join the list by clicking on the link below:

http://www1.ietf.org/mailman/listinfo/p2psip

The current mailing list archive can be found at http://www1.ietf.org/mail-archive/web/p2psip/current

The old mailing list archive can be found at http://lists.cs.columbia.edu/pipermail/p2p-sip/