[Wikiversity-l] GNU Free License vs. CC Attribution

[James Neill]

I realise this isn't a new topic, so feel to point me to 
further/background reading...

but what are the implications and legal subtleties of the difference 
between the licenses used on WV (GNU Free) and WE (CC Attribution)?

I would like to prepare a proforma letter to send to owners of copyright 
material which I use in my teaching (e.g., an image in a presentation), 
requesting permission for them to release the IP into a free culture 
license which would it to be uploaded into Wiki Commons or elsewhere as 
appropriate. My hunch is that > 50% could give permission.

If there is such a letter you know of or can share, please let me know.

Obviously it would be important for such a letter to cover all 
conceivable licensing contingencies.

Is the solution to dual-license materials? And could that be done, 
practically?