Web 2.0 v. Web 2.0
Web 2.0 t-shirt here.
Wikipedia on Web 2.0 here.
Blog of IT@Cork, organzation that received demand letter from CMP (parent of O'reilly) re use of WEB 2.0 to describe its IT@Cork Web 2.0 conference, here.
O'Reilly essay: What is Web 2.0
Most recent post from O'Reilly.
Cory Doctorow on the controversy.
IMHO, the 2005 O'Reilly piece begins and ends the discussion. If you coin and promulgate a term, you can sell it as a buzzword or you can sell it as a brand, but under trademark law, it's virtually impossible to do both. (And if I want to promote the Trademark Blog Web 2.0 Conference about protecting trademarks in the Web 2.0 space, then I will cite the O'Reilly essay as Exhibit A as to how I am using the term to describe a quality of my offering.
p.s. CMP is a trade publication specialist. It owns trademarks like VIDEOGRAPHY and CALL CENTER. Its lawyers are familiar with Section 2(f) of the Lanham Act.
Wikipedia on the term "Drinking the Kool-Aid" here.