There are two sections to the Nokia Device Hub. One shows a list of every device that you have connected to. The other shows a list of nearby devices that are using Wi-Fi or Bluetooth. It is those nearby devices that you are managing with this app.
For example, if your computer is using a Wi-Fi connection, it will show up on the Device Hub under the "Nearby" setting. In "Overview," you can see a list of apps that will allow you to connect your phone with your computer. Under "Apps" you will find a list of app that are available to be downloaded on your PC from the Windows Phone Store. Any device that supports Bluetooth or Wi-Fi can be picked up on by the Nokia Device Hub. You can pin a device to your home screen to quickly see which apps will work with it.
Check out the video below to see the Nokia Device Hub in action.
Nokia Device Hub out of Beta for the Nokia Lumia 630
source: WPXBox via WMPoweruser