Some of the big features include:
An updated User Interface – More along the social media line, with activity feed, like button, ability to follow other player, etc.
High Dynamic Range (HDR) – for life like visual performance. Your TV will need to support the feature in order to utilize it.
Folders – you can organize your library and sort you content.
Quick menu – lets you switch between windows/apps and allows for some actions such as gameplay broadcasting.
There’s more, like 2 step verification for better security, transfer over LAN, and more….