From the horse’s mouth
Bluetooth has just “cemented” the latest version of their wireless-personal-network standard at 4.2 .
This will be a major improvement for the “Internet Of Things” or “Internet Of Everything” because each device can have an IPv6 and 6LoWPAN stack to provide a direct link to an IPv6 network. It avoids the need to create a protocol-level bridge between a pure Bluetooth network standard and an IP standard, rather allowing access to the IP network and an Internet “edge” router in the same vein as a Wi-Fi wireless device.
As well, there will be some privacy-based improvements like a requirement for users to interact with their mobile device such as deploying an app in order for the device to work with Bluetooth beacons. There is also the ability to support dynamically-assigned MAC addresses to facilitate this goal. Another improvement is to provide faster data throughput which could speed up things like data synchronisation or provide a “fatter pipe” for more data.
As I have said before, this standard is “baked in stone”, and needs hardware, operating-system and software support for it to take off. Some functions can be integrated in to earlier Bluetooth iterations in order to provide some of the new features to existing devices.