YouTube is getting an update, but not in the way that you'd expect. It isn't bringing along any new features or showing up to the party with a nice new user interface to wow the users. This update is more or less on the backend of things that you won't immediately see, but it does still affect users as YouTube's changes are simply set to use HTML5 as the default video player technology instead of Adobe Flash. Google and YouTube started using HTML5 a little more than four years ago, but hadn't resorted to completely defaulting to HTML5 at the time because there were some limitations called adaptive bitrate hindering this alteration.
YouTube no longer has these problems with adaptive bitrate, which is what would allow users to watch videos with less buffering, and have officially defaulted to using HTML5 over Adobe Flash for YouTube's web-based video player. For the end user, what this means is better support for more devices in the long run, which is always a benefit. This includes but isn't limited to using YouTube on video game consoles like Playstation 4 and Xbox One, as well as other devices like the Chromecast, and in the most popular web browsers like Chrome, Safari 8 and Internet Explorer 11.
Also as part of this change to HTML5 as default, video load times should decrease, but it will also allow users to view and stream higher quality resolution videos while using less bandwidth. What that translates to is the possibility of 4K videos at a smooth 60 frames per second while still maintaining faster load times. This will cut down on the time you have to spend waiting for your browser and YouTube player to render the high res videos you want to watch, which will allow more time to enjoy the content and save you more time for other stuff. New features and designs are always nice, but it's these types of changes, the ones that make the website run smoother and function more efficiently that make a real difference. These changes should be immediately live, so if you start to notice a smoother user experience while using YouTube on all your different devices, this is the reason why.