Good: Plug phone into dock, phone interface disappears, desktop interface comes up. Unplug phone, and it reverts. You carry all your files with you. You go to a dumb monitor + keyboard + mouse anywhere and *poof* you have your desktop with you, and it's online because your phone has data. Yeah, it'll be a bit slow - so don't do heavy number crunching and you're fine. And they'll need to make it impossible to run phone apps in desktop mode or vice versa. Some things must be disallowed (although crafty software could intelligently flip between the two).
Bad: phone has desktop interface; or desktop has phone interface.
Which will it be?