Harry Pierson talks about why he hates the term Web 2.0:
First off, it’s a pure marketing buzzword. It was originally coined as a conference name. In a way, the fact that is has no underlying meaning is a good thing, because it gives people argue whether it really exists or not. In a way, it’s like the word “multimedia” back when we were first putting CD-ROMs into computers. There used to be lots of discussion if one thing or another truly was “multimedia”. Now, we don’t really worry about categorizing it as the marketing buzz around the term is long gone.
I'm not sold on the term either, but Harry covers a lot of the same areas of contention that I have, so go read his post. What about you, as you sold on Web 2.0?