One major piece of news is that this new spec fixes the broken key exchange during the pairing process, which made Bluetooth devices vulnerable to passive snooping. [1] It now uses ECDH for key exchange. [2] This is big because one of the main proposed use cases for BLE is medical devices, and now they can be secured.

[1] http://lacklustre.net/bluetooth

[2] BLUETOOTH SPECIFICATION Version 4.2 [Vol 2, Part H] p. 1342