Foursquare's game mechanics do get old, and they really haven't done much to change them since launch. I started playing Foursquare in March '09, was sick of the badges a month or two later, and haven't cared to check in much since.

Granted, I know plenty of people who still play Foursquare religiously, but I suspect they'll burn out on the gameplay too eventually. It's very hard to keep a game engaging over multiple years. I have nothing against Foursquare, I just hope they have some plans to mix things up.