The biggest update for the Shield Android TV is definitely the Vulkan API support, which should provide much need performance boost and is actually Google's API of choice for Android platform.
In case you missed it earlier, Khronos Group's Vulkan API is partially based on AMD's Mantle API and it is a low-overhead API, which gives developers a better access to hardware and reduces CPU workloads.
Nvidia has already announced its commitment to Vulkan API, providing drivers for Windows 7-10, Linux as well as Google Android OS.
In addition to the Vulkan API suport, the new Shield Android TV Android 6.0 Marshmallow update also brings upgradable storage and home screen customization, quick access to the power menu on the homescreen, seamless switching between surround sound and headset audio in Netflix app, wireless support for Shield controller when charging over USB.
It also brings improved color support for YUV 4:2:0 video playback, option to set 1080p 60Hz resolution on Ultra HD TVs and set RGB Full Range and improved support for Denon receivers and CEC volume control for more audio receivers.
In addition to these, Nvidia has added a couple of new Android games which are now available including Real Racing 3, Grand Theft Auto: Liberty City Stories, Oddworld Munch’s Oddysee, Dead Effect 2, Minecraft Story Mode and Metal Gear Rising: Revengeance.
Nvidia was keen to note that Square Enix titles are coming to Geforce Now, including Tomb Raider which is now available as well as Lara Croft and The Guardian of Light, Murdered: Soul Suspect, Sleeping Dogs and Quantum Conundrum, which are coming soon.