This year, Creative Commons unveiled a new initiative called "CC+". It is not a license. It's a "protocol", although it's so simple that it almost doesn't warrant the term. Basically it specifies a standardized mechanism to sell further rights for works under Creative Commons licenses. One application of this technology could be to enable "collective patronage" models like the one that brought us the Blender free movies to be extended to a much larger pool of Creative Commons licensed material.