The March update for Xbox One is quite a hefty one. Not only does it focus on improving the Live experience in time for Titanfall, it promises to add new features (like Twitch) and tweak OS features. The update is going live tonight.
For example, the update will introduce support for Dolby Digital sound through optical out and HDMI. In addition, the update will add support for 50Hz output, fixing the framerate issues some users have had in Europe while watching live TV through the console. Sound bars can now be automatically set up as well.
Perhaps the single most important update for me is the ability to adjust how much you can adjust the volume through the Kinect voice commands "Xbox volume up" and "Xbox volume down." Finally, no more two point increments!
For a more comprehensive look at all the new features added in the update, swing by the Xbox Wire.