It's looking like Plone/ZODB would need too much modification and
testing at the current time to move in to P2P.
The most promising environment in our research so far are frameworks
built on the Squeak language which is used by the OpenCobalt project (a
P2P collaborative 3D world).
Thanks for all your feedback and advice, and happy new year :-)
For more information about ZODB, see the ZODB Wiki:
ZODB-Dev mailing list - ZODB-Dev@zope.org