Suunto continues to expand their Ambit line of GPS fitness watches. The current Ambit2 comes as the Ambit2, the Ambit2 S (S is for multi-sport) and the Ambit2 R (R is for running). Now, they're getting ready to add Bluetooth to the Ambit 2 and they're going to call that watch the Ambit 3. The Ambit3 will continue to support ANT+ fitness sensors and the added Bluetooth capability will give it additional functionality (such as linking to your smartphone app, connecting to other Bluetooth Smart sensors, etc.)
The Ambit3 will also feature an integrated activity tracker (like a Fitbit) right into the watch. GPS watches like the Polar V800 and the Garmin Forerunner 15 already includes this activity-tracking feature.
Overall, the Ambit3 will look just like the Ambit2, so I'm not sure that you'll be able to tell the difference unless you flip the watch and look at its back cover.
I suspect that most fitness GPS watches will eventually incorporate Bluetooth so that they can communicate with smartphones. Plus, they'll incorporate some type of activity tracking capability so that you don't have to clip on a separate Fitbit to quantify your daily movements. They'll be waterproof to support swimming and triathletes, so it'll be nice to be able to track your activity, even when you're in a swimming pool. Right now, there are very few options for wearable activity trackers that are waterproof for swimming.
We'll be seeing all sorts of new watches coming out this fall for fitness enthusiasts. Google Android Wear smartwatches (which have touch screens, Internet connectivity, and all types of apps) that lack an internal GPS or robust waterproof capabilities for swimming. Apple iWatch. More watches that measure your heart rate right at your wrist (like the Mio, Basis, TomTom Cardio, Samsung Galaxy Gear, and others).