No, what happened was that a lot of people said "web 2.0!", a bunch of other people said "AJAX!", and only the AJAX thing actually happened. Web 2.0 meant the semantic web, not the asynchronously loaded web.
For as far as i remember 'web 2.0' meant replicating Mac OS X's Aqua on the web (very poorly, of course) with gradients and shadows (not necessarily through CSS, thanks to IE6, but it helped) and unnecessary javascript everywhere.