I think the luminous-landscape is the first website I've seen that has posted a full disclosure online.
http://luminous-landscape.com/about/disclosure.shtml
The US Federal Trade Commission will now require blogs to make full disclosure of their relationship with advertisers/manufacturers on their websites and I think it's going to be a very good thing for all of us. Not surprising but the theory that some "review" sites are money making machines in "disguise" seems to be a valid one. The purpose is to make money not really to inform.
Even when the site says they are "independent" and "free" from biases to review a product it turns out that the manufacturer's pay the plane ticket and accommodations for a "visit" to the factory. How can that not influence your "review" of a product? And they get to keep some things that they "review".
If Nikon was paying my plane ticket, hotel, and food for a visit to their Sendai plant how could I give a bad review of a product if they say they will fly me out again when the D4 is ready for a sneak peek? Hell even if canon flew me to Japan I'd probably start capitalizing the c in canon again ;^)
I wonder how dpreview is going to play around this rule. Their servers aren't in the US but they are owned by an American company so not sure if that's enough to force them to comply. Really makes you wonder about some of the reviews doesn't it?