I've been talking this over with some of the staff and so far they all seem pretty keen on the idea.
Its basically what the title says, a game that is built by the community for the community. Participation can be anything from spriting and faceart to just mapping out a town. Everything a game needs to be completed, RRR Needs You
(There was also the suggestion of Rev Points for participation, though that hasn't been confirmed).
So basically this post is to establish who would be interested in such a project, what engines you have access to (could always download a demo of another if we end up using one you don't have) and really just any ideas, suggestions or questions you may have.