Development of Creative Commons licenses

[Anthony <osm AT inbox.org>]

On Thu, Dec 29, 2011 at 2:57 PM, Mike Linksvayer <ml AT creativecommons.org> 
wrote:
> One of the reasons some form of
> BY-SA->GPL compatibility is interesting is that some want
> source-requiring copyleft for non-software, it isn't reasonable to
> make source requirement for all BY-SA use, nor is it reasonable to
> create another incompatible copyleft pool. If you want to require
> source, use the GPL.

Why not a CC-GPL, which is (one-way) compatible with GPL?

One of the advantages of CC-BY-SA compared to GPL is that it *doesn't*
have the sometimes onerous requirement to share source.

Something to keep in mind is that the "source" of a CC-BY-SA work (the
preferred form for making modifications) might in some cases be
thousands of times bigger than the non-source version of the work.