It appears that the upcoming Nokia Amber update for the Nokia Lumia 520, 620, and 720, not only brings FM Radio support to the Windows Phone powered devices but also Bluetooth 4.0 support as well. In fact, the update will also add explicit support for Bluetooth Low Energy, a technology that is used to communicate with accessories such as heart rate monitors, fitness monitors, and temperature sensors.
It seems that this new feature will be made available via the upcoming Nokia Amber update due in August, rather than the upcoming Windows Phone 8.1 update. Nokia reportedly revealed this information during a blog event in Hong Kong and also mentioned how Nokia Amber will improve picture sharpness in the Nokia Lumia 920 handset. The update is also set to automatically improve the color temperature of photos, improve camera focusing times, improve photo quality when zooming in, and improve the battery life of the handset.
No word on when we can see the Bluetooth 4.0 and Bluetooth Low Energy support on the Lumia 920, 925, or 928 set of Windows Phone devices. However, Nokia Amber is rumored to be rolling out in August for the Nokia Lumia 520, 620, and 720.Further reading: Nokia, Windows Phone