There is a great article at Arstechnica explaining the new Bluetooth Core Specification Version 2.1 + EDR that has been released by the Bluetooth Special Interest Group.
Why is it important to people interesting in ultraportables? Quote: Fully backwards compatible with Bluetooth 2.0, version 2.1 offers lower power consumption and an improved device pairing experience. A new feature called “sniff subrating” optimizes battery life, which the Bluetooth SIG claims can result in a five-fold increase in battery life for peripherals including keyboards, mice, medical devices, and watches.
Better battery life and device pairing. Suprisingly, some current Bluetooth devices can be upgraded to 2.1 with a firmware upgrade.