If you rushed on CC licenses because they're cool, did you take the time to read them before choosing one?
Dave Shea, who launched the CSS Zen Garden, released the CSS files under an Attribution-ShareAlike license from Creative Commons. But now Dave complains that someone wants to use them as is in an open source CMS.
The comments attached to Dave's post are enlightening of the misconceptions regarding CC licenses. It's only at #7 that someone hints that picking the by-sa license may not have been a good idea, at #8 that nothing illegal was done, #8 and #12 that you cannot override CC licenses with your own terms, and only at #17 that the CC licenses are irrevocable!
I think many people have overlooked the fact that there is no legal way to revoke a CC license. Apply one to something once, it will stick forever. This is actually a good protection, for those licenses are to foster creative reuse and nobody wants to receive a cease and desist letter for something that was once published in this spirit.
CC licenses are legal contracts, you should read the fine-prints carefully.