The new 2015 Evolution Kit (SEK-3500U) has an octa-core processor inside and will upgrade the TV operating system to Tizen. Tizen is a new multi-device platform developed by Samsung and Intel. The Evolution Kit also adds VP9 decoding support, which allows owners to stream YouTube in 4K for the first time.
There is another major change for owners of high-end 2014 TVs such as HU9000, HU8700, and HU8550 because SEK-3500 apparently (1, 2) also enables the TVs to process the new PQ format used for HDR content.
Samsung SEK-3500 is available now in the US for $400 and looks like a nice upgrade for owners of high-end 2014 TVs. The same Evolution Kit is coming to Europe for €399 Euro but no release date has been announced.
2015 Software Update to the Tizen Operating System with new redesigned Smart Hub
Faster New Octa core processor
Updated Touch Remote with new pointer operation
MHL 3.0 connectivity for connection to mobile devices
HDMI 2.0 ports that support 4K Video @ 60p
HDCP 2.2, MHL 3 and VP9 Support