What's keeping many people busy is the meaning of "commercial or non-commercial" use in the Creative Commons license with the 'nc' restriction.
In my opinion, and after discussions with other people, i think that every non-profit and public environment is non-commercial. And in a commercial environment, as long as there is no direct financial transaction involved, it is allowed to use the non-commercial factor, ie. playing music with a 'nc' tag in a commercial restaurant is allowed, as long as they don't sell this music, ie. asking a contribution in the bill (they still have to hang out a playlist though).
Anyway, it's difficult stuff, and the people @ CC are aware of the fact that there's a need for a more precise definition of commercial and non-commercial, so they launched a research study that "will explore differences between commercial and noncommercial uses of content".
You will find the full press release here.
Also have a look at a discussion about this item at Molly Kleinman's blog "CC HOWTO #2: How to use a work with a NonCommercial license". You will notice in comment 8, that the Dutch collecting society Buma/Stemra is rather taking a capitalist point of view, ie, almost everything is commercial, even my website netwaves.org, because of 2 silly Google ads.