From the New York Times, reporting from the iCommons iSummit in Rio de Janeiro:
Since the introduction of the Creative Commons concept in 2003, some 145 million "creations" have been registered. More than 100 million of those licenses have been issued in the last six months. Mr. Lessig said that blogs accounted for the largest number, followed by images and then music, although the video sector is growing.
Read more here. This shows that the Creative Commons licenses are definitely making an impact and potentially reshaping how people view copyright and the creative process.