But seriously, starting a journal is not so much about the engine, but more about the community to drive it.
So... volunteers? Step forward.
it is not really so much about volunteers (even though I am pretty sure that many members of this list would gladly help the editorial board), but rather of a practical wider impact, that is of an academic community which is going to receive the journal and read it (push rather than pull model). Perhaps it can be constructed around Wikipedia community, but it is not a matter of volunteering, but rather of clever sending out the message, once the journal is already out there. A question remains, whether starting a new journal from the scratch has additional benefits over supporting an already existing "Journal of Peer Production". I'm not certain either way, since there are pros and cons to both solutions, but it definitely is much less work to focus on a project which at least solved some of the startup problems :)
best,
dj