The NY Times has a worthy read exploring the diferences between product placement and product integration. The article points to the site productinvasion.com set up by the Writer's Guild of America. I really love the Subservient Donald video!
Product placement/integration is a confusing area. I'm not sure how far is too far is too far in the integration of content and advertising. There is a line somewhere. I guess, at the end of the day the customer will decide whether to watch and buy or not.