An update for the NVIDIA Shield Tablet is available now which as always "contains important enhancements and bug fixes." This is software upgrade 1.2.1.
The features in this update are as follows:
Improved WiFi performance on 5GHz band
Performance optimizations for encrypted devices
Fixed intermittent charging issue
No big changes this time around, but as always, its nice seeing the NVIDIA is constantly at work improving their products. This has been apparent recently with the announcement that the Shield Tablet will be receiving an update so it can run Android 5.0 Lollipop.