Actually google is merging this with google places for better access and better utilisations of resources available.Rolling Hotpot into Google Places helps simplify the connection between the places that are rated and reviewed and the more than 50 million places that already have an online presence through Google Places—places that millions of people search for and find every day on Google.
So,one less service to remember.
From their blog
Though the name Hotpot may be going away, you can expect even more “Hotpotness” in Google Places. We have big plans to continue adding more features to Google Places that make it even easier to rate, discover and share the places you love whenever you’re using Google. So stay tuned to the new Google Places Blog for product updates, tips, tricks and news from our city campaigns.