As an avid user, fan and subscriber to Foursquare and the future of location services I am both a promoter of the site while being a constant reviewer of functionality.
When Foursquare launched the leaderboard was the place to see how you ranked against other early adopters. You often did not have a long or strong friend list to compete against and badges were very new. Swarms were hard to come by.
Now badges are gaining traction with some even competing for the number of accumulated badges. Points are slowly becoming obsolete. I want Foursquare to stay ahead of the pack and deprecate points and begin placing better partners and perks.
The AMEX weekend for small business was a marketing hit. Coupons at local restaurants is a huge bonus and keeps people coming back. Rewards for verified mayorships are harder to find and should be a growth area.
What I need from a location service is the building of recommendations built around my learned check-in behavior. Learn the tags of types of places, areas they are in and begin expanding my circle. Pick something outside the normal radius, suggest adjacent type tags of foods or activities.
Become not only a place for me to say where I am, but a place to look for the next place to visit. I use Foursquare to not only announce my location for on the fly meet-ups, events or fun, but I began long ago to use the service to place markers on places I really liked and want to visit again in the future. (I wish they would buy sub-services like Foodspotting to match what I like at the locations I check into).
Foursquare has become an event logging, taste building and location service. I am only giving suggestions to maintain the growth and usage before something else comes along that scoops that part up.