Owners of Nvidia's Shield Portable, take note: the handheld-on-steroids is getting some love today in the form of an Android 5.1 update. The new OS should give owners access to all of the new features in Android 5.0 Lollipop and the minor fixes and tweaks in the point release. A new version of the bundled Twitch app is also installed by default.
The update does remove a few features and apps from the Android KitKat version of the Shield software. Built-in apps like Sonic 4, Expendable: Rearmed, and the Android Browser are no longer installed in the 5.1 image (nor will they work at all, apparently). Nvidia also removed Miracast streaming functionality in favor of Chromecast support.
For those who don't like Android 5.1 on the Shield, an Android 4.4 recovery image is available as a rollback option. Nvidia warns that both upgrading and downgrading operating systems on the device will wipe all locally stored data, so be sure to run a backup of some kind before moving in either direction.