I'm thinking this thing should absolutely come with a video-out on the device itself, without the dock.
It should be possible to take it to my friend, take it out of my bag and hook it up to his TV with (mini)HDMI and have a gaming night right there. I'd also want to be able to hook it to my PC monitor for a quick gaming session. Everywhere you see a screen you should be able to hook it up. That's a bigger local multiplayer incentive than crowding around that tiny display.
If they exclusively feed video-out through the dock, they are making a mistake.