Some of this same reasoning applies to wikinews. But for wikinews, a really *big deal* is compatibility with Wikipedia. (Or, am I wrong about that? How often will a news story really need to have content from wikipedia that exceeds ordinary fair use or quotation rights?)

I don't know of any clever solution which gets us both advantages.

License stories which use Wikipedia content under the GFDL, and license those that don't under CC-BY.

Anthony