- All new revisions are released with this license statement:
This page is released under CC-BY-SA. Depending on its editing history, it MAY also be available under the GFDL; see [link] for how to determine that. [end quote from Richard]
This allows us to not duel license anything added to wikipedia after the switchover so if the switchover is november 30 you can determine if the article is duel licensed by seeing it has been edited post Nov 30 2008. That would appear to simplify matters.
So you're suggesting we dual license everything written before the switchover and then license everything after that under just CC-BY-SA? That would be nice, but I think it contradicts the agreement with Richard:
"* ALL contributors agree to the following:
Wikipedia can release their newly written text under both GFDL and CC-BY-SA in parallel. However, if they imported any external material that's available under CC-BY-SA and not under GFDL, Wikipedia is bound by that."
That specifies "newly written text", which I interpret to mean text written after the switchover. Although, interestingly it says "can" not "must", so contributors have to give WMF permission to release it under GFDL but WMF can choose not to. I'm not sure that's the intended meaning... (I'm also unsure of the legality of "Wikipedia can release..." compared to to more usual "By clicking submit *you* are releasing..." [assuming "Wikipedia" actually means "WMF", obviously "Wikipedia" can't release anything since it's just a website and not a legal entity].) If that is the intended meaning (which would be strange, since it doesn't actually restrict WMF in any meaningful way), then your idea should work.