Yes, if you have an internal bluetooth card, you do not need to plug in the usb bluetooth dongle, which comes with a bluetooth mouse.
I liked this feature. However, for now, I have stopped using my Bluetake BT500 bluetooth mouse, because the battery life is quite short. I was using rechargeable batteries, but charging batteries everyday became a chore.
I an curious as to the battery life, which everyone else is getting on their BT mice.