I don't think the author of this book is the person who coined the saying 'black swan' but that isn't really important. What is important is what he's trying to say, that we tend to ignore the impact of highly improbable events, mostly because we aren't able to predict them. The saying comes from the fact that we thought all swans were white until somebody found a black one and our definition of a swan was turned on its head.
I think this book has become a commercial success due to a little bit of serendipity, it arrived on the shelves of bookshops at about the same time as the financial meltdown kicked off, arguably a black swan in itself (although I'd argue quite a few people saw this coming but not many realised how serious it would become). I think that's what they call ironic.
Anyway onto the book. For me it only really comes into itself in the last few chapters where he gets into the technical details of our failure to predict, which is mostly down to our use of the Gaussian/normal distribution where it isn't applicable. We should be using fractals instead (before reading this I thought fractals were purely used to produce pretty pictures). The earlier chapters could have been shortened more for my liking, there's only so many ways you can say we fail to take notice of the impact of the highly improbable (except after the event when we manage to produce a narrative to explain why it happened and wasn't totally unexpected). I guess I'm more interested in the hard facts, rather than the philosophical musings. But that said, it's still a very good read and certainly makes one think. I guess the important point is that we should try to increase our exposure to potential positive black swans (business opportunities etc) whilst reducing our exposure to potential negative ones.