youfoundjake - 4:17 am on May 14, 2009 (gmt 0)
The ability to add ratings data to the snippet will benefit the user. We are often reminded to build for people, not engines, and playing the devil's advocate here, the extra information contained in the snippets I think will help the click-through, and to be clear, will NOT improve rankings.
As I mentioned before, Yahoo tried this with SearchMonkey. The simplist way I understood it to be was, when someone does a site search with the yahoo search box embedded in my site to make a function call to a site that contains reviews, associate those reviews with particular search terms, and display your site page, with the snippet containing the review info from site:B, triggered by a certain keyword search.
I thought to myself, "wait a minute, yahoo wants me to customize my snippet to included microformat data from another site, and thus pre-populating the SERPS of the local searchsite with data that is more user-friendly" and I wondered why I should be building Yahoo's search results..and I said forget it..
I think google is doing the same, but instead of it being a site-based search (widgets site:example.com) like yahoo, it's the actual SERP..