I'd like a rating system, too. I'd also like to know if the cache is in a buggy area, a dry area, in a tight area, an open are, etc... The current terrain/difficulty rating is wildy inaccurate. I've hit 4/4 caches that were much easier to find and get to than some of the 1/1 caches out there.
Simply put: I'd love to search for caches on a large variety of statistics, such as:
User Rating, Newest, Most Recently Hit, Days Since Last Hit, Travel Bugs, Insect Pests, Wet/Dry, Flat/Hilly, Enclosed Space/Open Area, Estimated Distance from Parking, Dog Friendly, Mountain Bike Accessable, etc, etc, etc....