Right now, SpaceX is only reusing rockets to a limited degree -- it's disposing of vehicles after a short while when they're unlikely to survive their next flight. With its latest launch, though, it got lucky. Elon Musk has confirmed that the Falcon 9 first stage from the GovSat-1 launch survived its intentional water landing. It was only meant to test a "very high retrothrust landing" for the sake of protecting the drone ship and was expected to meet an untimely end, but it appeared to have survived largely intact.
Musk hoped the booster could be towed to shore, although there's no mention of what happens if it comes back safely. We wouldn't count on much happening, however. It doesn't exactly look like it's in a healthy state, and SpaceX isn't about to preserve every rocket with a special story behind it.
As it is, the company's eyes are elsewhere. SpaceX is poised to launch Falcon Heavy for the first time on February 6th, and the successful GovSat-1 effort makes sure the Heavy launch can go ahead without hiccups. The rocket recovery is really icing on the cake.