This isn't even a emulator, its a simulator with its own binaries.
The SDKs are the same, so iPad, iPhone and iPod Touch can use the same APIs and the OS will prevent you from doing stuff you can't do on one of those devices (the iPad for example can't show a transparent menu bar).
I have just "converted" an App from me for the iPad, by converted I mean: Just change the position of the elements to fit the screens. It's really easy and took five minutes, here is a screen:
http://img5.imagebanana.com/img/3quyfvvi/Bildschirmfoto20100128um14.58.55.pngThe same App can run also on the iPhone and iPod Touch without a change!
