I just rolled out microdata support to the new marketplace for products, reviews, pricing offers, etc. The most visible thing that will happen because of this is Google search results will show average ratings/stars for your products right in Google search results. For example, you can see what a Google search would look like for this product: http://www.google.com/webmasters/to...formula-make-money-within-hours.14/item&html= Individual reviews as well as pricing info is defined in the microdata as well now.
Extended microdata to the Buy/Sell/Trade area, so pricing will show in Google search results for things like so: The low price is the next minimum bid amount and the high price is the buy now price.