Not much, apparently, if you go by the recently released film of that name (actually titled "What the #$*! do We Know?"). Brian Godawa, on his "movieblog", gives a detailed review of this "hybrid documentary/drama" that is making the rounds of the college campuses spouting half-truths about quantum mechanics and other disciplines. Scroll down about a quarter of the way to reach the review. Says Godawa, "This movie is riddled with more holes of hypocrisy and contradiction than Bonnie and Clyde were with bullets."
Meanwhile, over at Blog and Mablog, Douglas Wilson takes a healthy look at what the reality of human knowledge is and how it works in "Backs to the Future". I particularly like his comments on the nature of scientific knowledge, a concept which the makers of the above film seem to have forgotten, that being "...some of the things that we think are slam-dunk certainties will almost certainly turn out not to be. E.G. Stanley once commented (with some acid in it) that the history of scholarship is the history of error. And was it Max Planck who said that science advances funeral by funeral?"
Update: I was peeking in over at Defective Yeti (my second favorite blog title...the #1 is here) and saw his "Bad Reviews" section, which, not surprisingly, included an excerpt of a bad review for "What the...?", saying "Like being stuck at a science fair, with a 5-year-old on one side asking questions and his hippie parents on the other fumbling to answer them." -- Jon Niccum, LAWRENCE JOURNAL-WORLD