We saw the above screenshot of the next major update coming to windows phone, GDR3 (aka Lumia BitterSweet shimmer) leaked a few days back.
And today the guys at WPCentral got a video demo-ing the next update...
The main feature is the X in the multitask screen that now allows you to close background apps, the usual way was to go to the app and keep pressing the back button till it closed.
Now this is a better eased way of doing it.
check out the other features
Another video has has surfaced showing the next upgrade for WP8...