The newest Steam Client Beta Update from Valve introduces a couple of minor fixes along with the addition of a Virtual Reality mode to the View menu.
The March 17 update fixed a glitch with the message shown when unblocking people and added improved keyboard accessibility in the block or unblock dialogs, as well as improved the initial startup time when launching Steam for Mac users.
A more visible addition is the "Virtual Reality mode" to the View menu, accompanied by the removal of the "-vr" command line option. Note that the new mode will only appear if SteamVR is installed on the system and a supported HMD is detected.
The improvements in the Virtual Reality department don't stop here, Steam now supporting switching from desktop mode to VR and then back to desktop into Big Picture, as well as having added support for detecting when an HMD is being plugged in, after Steam has started.
Furthermore, the latest update has also introduced a lot of general improvements to the In-Home Streaming Beta functionality, adding hardware accelerated encoding via Intel QuickSync, mouse emulation for controllers, revamped some of the streaming options UI, also adding the option to disable streaming and a speed vs. quality preference setting.