Richard Prince’s “Canal Zone” paintings have been found Fair Use. This doesn’t mean a lot outside the US, where Fair Use tends not to apply, but it’s still good news.
See more here:
http://theartlawblog.blogspot.co.uk/2013/04/a-more-positive-take.html
http://www.theartnewspaper.com/articles/US-court-rules-in-favour-of-Prince-in-copyright-appeal/29342
And a more humorous take:
http://shaneferro.tumblr.com/post/48908136229/a-short-rephrasing-of-the-prince-v-cariou-appellate