Chris, come on man, what do you think is gonna happen.
Get a new set of same Tires and you will be all set.
Tires age like everything else. As the tires ages, the rubber changes its characteristics. I dont see anything very odd here as it sounds like you push hard on "the envelope" when you ride. Ride like that alot and you will break the envelope someday. Get fresh meats before those tires let you down for real.
I dont ride THAT hard so i (and many others here) dont need to worry about how long our tires maintain a nice predictable slide.