Ever since the dawn of the Twitch livestreaming age, it's seemed like a no-brainer for Steam to add some sort of quick and easy broadcasting option. And yet for some reason, (hint: it's Valve), Valve has taken its time. But finally, it's here.
Valve explained the new feature, called broadcast, on an update page. Finding a game to watch is as simple as trawling your friends list and selecting "watch game" (if they've set Steam to allow it) or finding someone who's made their streams publicly available by way of a game's hub page.