there is a Maemo 5 launch without a date announced, there is a Maemo Summit with a date decided but not necessarely linked to the launch,
there is a possibility to involve some community developers and representatives in the launch but that would involve an NDA at least to keep the date confidential...
Not only for now this case of Maemo 5, generic ideas on how to collaborate more and better around public launches and developer camps are also very much appreciated.