Pew put out a new study on Riding the Waves of "Web 2.0"  which I found out about from Micro Persuasion.  Took a look at the study and found it refreshing.

For one thing, there’s no line that separates a Web 1.0 application from a Web 2.0 application and the destinctions that exist depend more in our defination than any specific change in internet technologies.

I don’t recall seeing HitWise charts in other PEW studies that I’ve viewed recently but Riding the Waves of "Web 2.0"  does have a couple of charts from HitWise that show success of sites based on Web 2.0 concepts vs. those based on Web 1.0 concepts.

The Riding the Waves of "Web 2.0"  is only a couple of pages and an easy read, much different than some of the other PEW studies I have read.