Rabbi Jason Miller wrote an article in response to recent jokes made during the Oscars about the Holocaust, and asks when it is acceptable to make a joke about the most prominent tragedy of the 20th century, and possibly human history. The general answer by the Huffington Post readership seemed to be that it is acceptable as long as it is funny, which is usually how it goes in comedy. Some people pointed out that in "The Producers" there were many jokes about Hitler, but I would argue that they were Nazi jokes, not Holocaust jokes. Yes, there is a difference.
Of course, there were always a few haters to arrive with their Holocaust baiting and minimization. This is the Huffington Post after all.
I gotta say, I did Na-zi that coming! Eh? Eh?