NVIDIA has pushed Update 2.2 for its Shield Tablet Wifi/LTE via OTA (version 29979_512.4856) in Europe and US. This version offers support for Hub 4.1, new streamed PC Games, battery improvement and UI optimizations. You can download the full OTA zip of this update for both Wifi and LTE variants via the official download links given below.
Here is the full stock OTA image (not incremental) of Android 5.0.1 Lollipop for the NVIDIA Shield Tablet (LTE & Wifi-only) that can easily be flashed using a custom recovery like TWRP or Philz. Just pick up the appropriate update package below and flash it right away.
NVIDIA Shield Tablet is officially getting the Android 5.0.1 Lollipop update via OTA around the globe as a part of the new Software Update v2.1 that weighs around 90 MB. You can download the Zip file of this OTA for both LTE and Wifi-only variant via the direct download links given below and flash it manually using your stock recovery.