I've been observing that most of the websites designed in Web 2.0 have higher PR? Is it to do with Web 2.0 design or that Google loves Web 2.0 ??
Neither. Design has nothing to do with homepage PR and internal PR. Only the structure of the site can be responsible for internal PR, as well as linking directly to inner pages.
usually when its a very nice web 2.0 design, the website get hundred of high pr links from "galleries" there are tons of css galleries and most of them have a high pr homepage... anyway that's just an idea, but the PR has absolutely nothing to do with web 2.0 or not.. it's all about links.
yeah well funkymario has a good vaild point Anyhow its possible that web 2.0 would make it easier for users to find content, then link baiting would kick in
Well there is no direct reason why a web 2.0 website comes higher on PR. But there are implicit reasons why web 2.0 websites rank higher. I could think of followings 1) C2C (Content to Code ratio) is higher in Web 2.0 websites as they use CSS and no tables. This certainly has an advantage over traditional websites with tables. Search Engines do like a clean code ain't they? 2) Web 2.0 are attractive and they really do attract visitors more than traditional websites who often bookmark these websites or refer to others or circulate among their friends who in turn bookmark/refer and this whole chain goes on. 3) With pure CSS the websites pages render faster by virtue of having less code and not to mention that Google now consider the speed as one of important factor in SEO. To sum up I would say that even though there is not direct relationship between Web 2.0 and higher PR but in the background a web 2.0 design is bound to get notice not only by humans but also by search engines.
I think if you look closer at those web 2.0 sites you'll find they are better optimized for SEO and probably have more relevant backlinks. Designers are more aware of SEO issues today than they were when they designed sites 5 or 6 years ago.