This whole blog post came automatically through ThisNext.com, where they have a "blogit" button near products, and if you are with one of the major blogging services, you write the whole post right at ThisNext. The site itself seems clean and to work well. Google ad planner also shows traffic up by 50% in the last year. The idea is that expert and non-expert users recommend products and anyone can browse the recommendations. I didn't yet see how or even if products are really ranked or weeded out other than by number of recommendations and whether or not an expert recommends them. They do have a provision for companies to send them products to be ranked.
I think this idea is inevitable - people love to write reviews and I think product word of mouth is a natural outcome of social communities. They also run ads right next to products though, which would apparently be their source of income. This seems to dilute the idea a little.