Blogware has implemented Reviews and Review metadata in their tool. RVW was already supported as a MovableType plug-in, and through the Blam! publishing tool, which I've been using on Way.Nu for quite a while; but it's inclusion in the "standard load" or Blogware should help speed the growth of the standard.

The RVW specification is a module extension to the RSS 2.0 syndication format. RVW is intended to allow machine-readable reviews to be integrated into an RSS feed, thus allowing reviews to be automatically compiled from distributed sources. In other words, you can write book, restaurant, movie, product, etc. reviews inside your own website, while allowing them to be used by Amazon or other review aggregators.

There should be more than enough RVW metadata out there floating around at this point. The next step is for someone to build a decent aggregator that collating reviews of a particular topic or two. Because of RVS, creating aggregate rating scores and summarizing opinions should be very straightforward. It's really not in the best interests of Amazon, epinions and the like to loose control of their review content, but RVW makes controlling review content impossible in the long term. Anyone got some pull at the Google skunkworks?