Bluetooth 4.0 is actually composed of three different specifications: classic Bluetooth, high-speed Bluetooth, and Bluetooth low energy. Their attributes can be combined in different ways to suit the product they're used in. For instance, a sensor in a pedometer will use just the low energy tech, while a watch will combine that with classic Bluetooth when communicating with your PC, and a Bluetooth-equipped laptop could combine all three.
Devices relying on Bluetooth low energy are expected to offer battery lives measured in years, but for other devices supporting the widest range of uses, like smartphones and laptops, the improvement is not expected to be so drastic. On the improved range claim, the Bluetooth SIG said manufacturers can tweak this when designing Bluetooth 4.0 devices so that it will be extended to a distance of 200 feet and beyond.
The full Bluetooth 4 specification is expected to be completed before June 30, with devices featuring the technology first hitting the market in late 2010 or early 2011.