The Steam Client Beta has been updated with the following changes:
Homescreen - Big Picture Mode
Added a new 'Big Art Mode' option for the home screen. This can be enabled in Settings > Home.
Added Personal Calendar to the Recommended tab on the home screen
Screensaver - Big Picture Mode
Added a new screensaver feature, accessible in Settings > Customization. There are two screensavers available:
I applaud valve for implementing features, and making them opt in instead of making me waste my time trying to figure out how to disable everything