See web-only content:
http://www.theatlantic.com/entertainment/archive/2010/07/a-holocaust-survivor-dances-at-auschwitz/59557/UPDATE: Alyssa Rosenberg points out that this isn't history's first example of dancing at a Holocaust site: Groucho Marx performed a two-minute Charleston on Hitler's grave in 1958.
This article available online at:
http://www.theatlantic.com/entertainment/archive/2010/07/a-holocaust-survivor-dances-at-auschwitz/59557/