I'd just like to say this: regardless of what the decision is, it is vital that we come to a consensus on the copyright/licensing issue. The worst thing we could do is debate something and then not come to a decision. That being said...
These licenses will allow some non-related party to sell our book without our consent (technically with our consent, because of the license): GFDL, CC-!NC, FreeBSD, Apache 2.0, CPL, TeX, CCDL
These licenses prevent that: CC-NC
No commercial use is in the minority. (Granted, quite a few of these are software licenses, though)
The two main variables here are commercial use and copyright reassignment.
If we require copyright reassignment: The leaders control copyright over the project, which means they have complete control in licensing. At any time, they may change the license (possibly to a non-free one) for all future versions of the work (although the original license usually will protect our right to continue distributing the work under that license). While this may seem like a worst-case scenario, it has happened before, and that's the trouble of assigning copyright: you loose control. If you were solely responsible for a chapter in the book, you have
no copyright over it, and cannot relicense it alternatively or use it in any other way except under the terms of the original license. It works the other way: if a license is found to be defective, only the leaders need to unanimously decide to change the license to a newer version.
Just a personal note, if copyright reassignment is required for this project, I'm gone.
If we require no commercial use: Under the terms of this particular license, no publisher may sell the book for profit, and the host that the book is hosted on may not have ads unless these entities are of non-profit status (are there that many non-profit publishers out there). This license, however, does not preclude another license which does allow commercial use, usually with publishers in the form of a contract. This would have to be negotiated by the copyright holders.
Put them together, and...
No commercial use and copyright reassignment would only require the group of leaders to handle contract negotiation with a publisher.
No commercial use and no copyright reassignment would essentially stop publishers from publishing our book unless they were non-profit, as there would be no way to coordinate all of the copyright holders in the creation of a contract with the publisher.
Commercial use and no copyright reassignment (what I like) only needs one party to negotiate with the publisher in order to get the book going. Much of the contract would be unnecessary as the rights are already granted, but we'd still need someone to work with the publisher (not a small task).
This is precisely how the
Subversion book works, which is published under
free (CC-BY, note no NC clause) license and by
Oreilly (who I imagine would publish our book under normal circumstances anyway).
Commercial use and no copyright reassignment WORKS. That's why I'm pushing so hard for it.