I know that the "Kinect Adapter for Windows" is currently out of stock in many countries. I have made many attempts to contact Microsoft and finally received an official answer from the Kinect team:
It is not very specific, but at least some confirmation. I am sorry for any inconvenience this may cause, sadly this issue is completely out of my hands.The adapters will be coming back into stock sometime in July. I'm sorry I do not have more of an exact date.