The ultra low-power Wibree wireless standard founded by Nokia will become part of the Bluetooth specification. Once the spec is integrated into Bluetooth, low-power PAN (Personal Area Network) devices such as watches, toys, consumer health care devices and sensors will benefit from the extra battery life.

Wibree makes minor changes in the media access control layer of Bluetooth to deliver data rates of up to 1Mbit/second while requiring just 10 to 40 percent of Bluetooth's power consumption. Both Bluetooth and Wibree serve a similar range of around three meters, however Bluetooth can deliver up to 3 Mbits/s. 

Later it will follow up with a dual-mode spec that will require minor hardware modifications to the classic Bluetooth spec to support the lower-power Wibree. The changes will require less than a square millimeter of silicon. Not sure if mobile manufacturers will let you retrofit your existing Bluetooth devices by sending it back in. I doubt it.

Source: EE Times