tedster, here is my concern. This is supposed to only effect retailers right? So lets say I am in the digital widget industry. I am not an ecommerce site, more like an informative site and I depend on revenue from my ads rather than sales. So lets say a competitor decides to hire someone to go around the popular reseller ratings/reviews sites and bad mouth my company. Being that my company is not a retailer, I would not have any existing reviews, so these new reviews would be 100% negative, and no existing positive reviews to offset these negative reviews. So then if you do a google search for my company, you will get a bunch of results about how we have no satisfied customers.
Being that this only affected 100 or so sites, I sure would hope this would be a manual thing where as their algo can detect a trend and then an actual google employee can review the site in question to make sure they are not ruining a legit business for no reason.