Wikimedia has a strong tradition of consensus building, so I'd like to refactor some of the comments into a kind of checklist of things we may want to see done/resolved before migrating Wikimedia projects from GFDL to CC-BY-SA. Here's a first stab:
[ ] A "statement of intent" for the CC-BY-SA license. This could address, in my view, some of the concerns regarding Creative Commons' future stewardship of the license. If there was a clear statement that summarized the goals of a share-alike/copyleft license succinctly, then CC could also make a commitment to only change the license itself in accordance with that statement.
[ ] A clear path forward regarding copyleft on embedded media. Mind you, I would argue that the current (FDL) situation is already ambiguous and complicated. Furthermore, one could make the point that this is not strictly a requirement for migrating the _text_, but it could be a requirement for migrating uploaded media.
There basically seem to be two options under consideration: either clearly making CC-BY-SA a strong copyleft license, or making a separate license that meets those needs.
[ ] An improved attribution clause that works for wikis, e.g. some version of http://meta.wikimedia.org/wiki/GFDL_suggestions#Attribution_requirements_for...
[ ] Some improvements to the CC-BY-SA "frontpage" which includes the license summary. In addition to any clarifications that might be desirable, I've discussed with Larry before the possibility of clearly labeling CC-BY-SA as a "libre" license, in accordance with the definition at freedomdefined.org -- he has expressed support for this idea.
Anything else?