We heard Microsoft ran out of time in developing a notification centre for Windows Phone 8.
Its however amazing what a motivated hacker can achieve. Above we have a demo of a new app being worked on by Windows Phone Hacker Jaxbot. He does not explain the underlying mechanics of the hack, but notes that it does not require root access to the phone, presumably only needing the phone to be developer unlocked.
The app is still in the early stages of development, and he is taking input on his site here.