using "CC BY-SA 3.0" Licensed Art Commercially - Your Experience?

Assets: http://media.ryzom.com/
License Summary: http://creativecommons.org/licenses/by-sa/3.0/
Legal License Document: http://dev.ryzom.com/wiki/ryzom/Licensing#Creative-Commons-Attributions-ShareAlike-30

My research is providing mixed results:
- Some say, that this would require you whole project to be licensed by "CC-BY-SA 3.0"
- Some say, that this would require only all your Art to be be licensed by "CC-BY-SA 3.0"
- Some say, that this would require only the specific files to be licensed by "CC-BY-SA 3.0"

Question:
Does anybody here has experience using "CC BY SA 3.0" licensed content commercially?

Of course if I decide to use them, I will get real legal advice before hand.
For the moment they just make nice looking placeholder art, and I taught they would be nice for some other Developers as well.


Thanks

 

This. It says so right in the summary.

Always a good idea, but make sure it's from a reputable source. Not all lawyers are familiar with this field.