That notification center will come with Windows Phone 8.1, has been known since long time and we have multiple rumors talking about that. Now, WMPU has received above screenshot from an anonymous tipster which shows the notification center customization settings.
As you can see in the leaked screenshot, there is option of choosing up to four apps for quick access and showing notification. Disabling any of these app’s notification will not make the app’s Live Tile disabled. There is also option of showing notification over lock screen. There is something called “banners” which to me looks something like big rectangular notifications appearing on top.