This sounds like it's exactly what I'm looking for, and all the other ratings extensions all seem to be long dead. Really I wish Disqus would just add a better rating feature to their commenting system, but an extension would be even better. Let me know if you'd like a guinea pig, or need any help from a novice. Looks like you might have long abandoned this one though?
Topic on Extension talk:Reviews
I updated the notice on the page itself. It now links to the latest source.
Thanks! Looks like you put a good bit of work into it. Hopefully someone will take the reigns and finish it up. I submitted a feature request to the Semantic Mediawiki Dev list asking for a star rating addition to the property types. I think being able to have a similar star system like you created, plus disqus for commenting, would be a decent solution. Then you could also query for the average rating on a page, and display it next to results.