Taleb's book is basically anti-science, in the sense that he's making a (good) case about the dubiousness of the epistemology underlying the scientific method. In the colloquial sense though a black swan has just come to mean an event that most people didn't expect.
I've only read Fooled by Randomness and The Black Swan, but those at least aren't anti-science at all. The argument is that in physics as our ability to measure the world goes up, so does our ability to accurately predict it to an extremely high degree of precision, and we've relied on this fact to build an expectation that the same is true of all sciences, and this is simply wrong, especially because it looks like any fault in prediction is just a flaw in measurements. As soon as we humans making our imperfect decisions enter the equation, a treacherous but inherent element of pure unpredictability appears and unless we temper our faith in our ability to predict the world through models, we stay prone to being surprised by black swans.
