Google Caffeine when announced first back in August created the strong buzz among Online community, SEO folks, website owner's and many people started comparing their rankings with Caffeine and Universal Search. Too some Google Caffeine results were exciting and too many they didn't experienced much changes, but all were on same page regarding Caffeine quick, faster and accurate results, also the crawling were increased to much larger extent with relevant results.
Google made the Caffeine available to Power Searches and all other people till today at http://www2.sandbox.google.com/
Today I found Google Caffeine says:-
"We appreciate all the feedback from people who searched on our Caffeine sandbox.