This is thanks to the new BCM20730 Bluetooth chip developed by Broadcom. This is said to give keyboard/mice and other Bluetooth devices such as remote controls, game controllers and 3D active shutter glasses a potential 10-year battery life when paired with regular two AA batteries.
With USB emulation and Broadcom’s ZeroTouch configuration technology, accessories that use the BCM20730 Bluetooth chip are said to be usable right out of the box without the need for any special pairing procedure. The chip is currently in full production although we’re not sure when the first products using the chip are expected to start rolling out.