How do we develop ideas about long-term changes, prioritize them, and pursue them over time (through obstacles, sets of pro and con contributors, usability studies, &c)?
Discussion of problems and tasks on Wikipedia itself seems like a great idea to me. (though a lot of people do this now on their own blogs, on mailing lists, and elsewhere...) That way the first people to contribute to an idea can facilitate larger open working groups, and not discourage others from jumping in and fixing things.