Is the iphone 4s going to last me?(game wise)?

The expected physical lifespan of an iPhone is 2 years. Keep your info backed up and you can always get it back if you need a new phone for whatever reason. Apple updates its software on a somewhat regular basis. If an IOS 7.0 comes out odds are it will be compatible. As of now it can handle 6.1.3 but it's hard to say. Apple products get out of date quick. You could just spend the extra and go for a 5.