Don't hold your breath. Its not designed by Konami, so it will not be a like the arcade. In fact I've already herd conflicting reports...and this article and pic make it look a lot worse than I expected. First I thought it was suposed to have a gyroscopic tilt sensor, but from the picture they show a lightgun lens optic. I imagine the screen will be flickering, reading the position via normal lightgun methods. Next the article says that the "special sensor" only tells when your head is looking through the scope (a proximity sensor)...and just triggers the zoom funciton of the game (big freaking deal). The point of the arcade game is to use both eyes, one looking through the scope at the magnified picture, and the other looking at the wide shot to see everything else around your target.
Without a mini LCD in the gun, and without a tilt sensor (preferably on a stable base...otherwise it will be a b!tch to calibrate) there is no way this will replicate the real arcade expierence. I'm not usually the pessimist, but be prepared to be dissapointed.