Up until now, you've always had to watch a live Google+ Hangout-On-Air like old TV: when it played and you needed to go do something, you couldn't go back and watch what you missed. And maybe the hangout just ended, and you wanted to see it, but you'd have to wait for the video to process. Well, no longer. Google Hangouts are now almost like watching a show on a DVR. You can rewind the live broadcast while it plays. And now, videos are processed as soon as they're done, so you can watch it almost immediately after. Also, the stream has been improved on mobile. There is one hitch, though.
New Google+ Hangout-On-Air Features: Better Mobile Stream, Live Rewind, Instant Processing
Mobile users will be glad to find a better stream on their devices now, which means higher quality video instead of the blocky image mobile users have become accustomed. They've also made it so the Hangout starts after you open up the page and when it's ready, rather than having to refresh a video with static that assures that the live stream will be starting soon. So lots of new features on these Google Hangouts.
The hitch is that the broadcast will take longer to get ready now, giving you a longer period of time where the "Start broadcasting" button will stay gray before it's ready to go.