[Engadget] Even though the laptop was off you can use the Auxiliary Display to check your calendar, view emails, control Windows Media Player, stuff like that. Obviously programs have to be written to interface with the display, but the Microsofties we spoke with said that the API will be open to software developers.

I sure hope the API is open. I can think of lots of neat apps for it already - imagine just integrating a wifi hotspot locator into this. Sweeeeet.