Web 2.0 is NOT ajax/RSS. Nor is it high-gloss, low-complexity designs. Web 2.0 is a movement in web development entailing high amounts of user interactivity with huge amounts of user-generated data. That is what web 2.0 is; no more. The things that people describe as web 2.0 are the things that came along with the movement.
The name of the movement, web 2.0, is probably causing the trouble itself...people think that they require new frontends to go along with the whole "Next Generation (2.0)" web backends.

Btw, this is when web 2.0 was thought of, and then implemented at a different date:

Originally Posted by Wikipedia Web 2.0, a phrase coined by O'Reilly Media in 2003[1] and popularized by the first Web 2.0 conference in 2004[2] , refers to a perceived second generation of web-based communities and hosted services — such as social-networking sites, wikis and folksonomies — which facilitate collaboration and sharing between users. O'Reilly Media titled a series of conferences around the phrase, and it has since become widely adopted.