Just heard from pgerts that a new version of the KK multicopter control board has been released on HobbyKing.
At a first glance, the only difference is that V2.1 is green, V3 is blue.
All the specs are the same, except the processor. The V2.1 came with a Atmega168PA chip, the V3 comes with a Atmega328PA. (Personally I have no clue what this means. Faster processing or more complex programming?)
The V3 has exactly the same layout as the V2.1, same size, same weight.
Price is currently at $20 (19.52 with buddy code) for V3, while V2.1 is only $15 ($12.44 with buddy code).
This is a new product, so there are no reviews yet. We'll see!
The kkflashtool webpage (http://lazyzero.de/kkflashtool) states that it supports HK KKv3.
Indeed the software is already compatible with the V3 board: