My first thought is that it looks an awful lot like the old Yahoo Shopping. The look and feel of Yahoo Shopping hasn’t changed a bit, just the results and the URLs. Even the Yahoo rating system was retained. The search results are very similar to the PriceGrabber site, though I did see a few minor variations. Default rank on product pages is definitely different, probably due at least in part to the different rating systems.
Since this change was invisible to the average shopper, meaning the user experience hasn’t changed, it’s difficult to think the performance of this traffic will change drastically. I think PriceGrabber’s results may be perceived as more relevant and there is some additional navigation so it’s possible that some improvement could come but only time will tell.