I'm really excited about this: we are organizing a Plone sprint in Paris in April at Ingeniweb headquarters !
No topics are planned yet because it depends a lot on who will be able to come. This will be done throughout January.
Please join the project and its mailing list if you are interested:
http://www.openplans.org/projects/plone-3-paris-sprint/project-home
And do not hesitate to make some topic proposal on it