What are your thoughts on the direction of Web 2.0 technologies with regards to SEO?

Web 2.0 makes a drastic change in SEO. Web 2.0 technologies has changed all the trends and also helped allot internet users as you know in web 2.0 there are so many features like blogging, RSS-Generated syndication, social bookmarking, MASH-ups, wikis and other collaborative applications, google Base and other free Web services , interactive encyclopedias and dictionaries these all features are very help full for SEO.