The main differences you may (or not) notice from 4.9 is a slightly re-worked settings menu, getting rid of the bland grey overlay and swapping it out with clear white. Other UI elements such as buttons in the settings have been tweaked, as well as spacing between items. Unfortunately, you'll be hard pressed to find any new features in this one folks.
New Post Creation Flow
Although technically this interesting titbit didn't arrive with 5.0, a new server-side change has been rolling out to users over the past few weeks. It's a new post creation flow, or in other words, a new interface for selecting who to share a new post with.The new interface divides people/circles and G+ Communities and displays personalised people/circle/communities suggestions based on how often you share with them. The search feature is still in place and is as useful as always with incremental search in case you need to reach someone that isn't found in the suggestions.
Checking for updates
To check if 5.0 is waiting for you, make sure to tap on "My Apps" in Google Play on your Android device. If Google+ is at the top of the list, hit the "Update" button and you'll be good to go.Let us know if you've spotted anything in 5.0 that we've missed.