It's not even entirely confirmed, but I am anticipating it too.

Will you be able to plug in your nunchuck to the lightgun or will it be a stand alone controller?  IF they combine the wiimote and the nunchuck on the lightgun, how will you be able to play games that have you shaking the nunchuck to do things in the game? IF you could plug the regular wiimote into the lightgun as an extension, would you be able to aim with both and aim at two different spots when you play a dual-wield shooting game?

Well the one shown by Nintendo awhile back had the Wiimote directly plugged into the shotgun. The Shotgun also had a control stick on it. So if the design does not change, then this thing will only be for certain games.

The one by Joytech, though, is just a shell. You click in your controllers (meaning the Wiimote and Nunchuck). So I wouldn't spend the money on this one because most games that require both controllers would be hard to play with this.

It looks like a fun idea, but will the light gun actually help you play games?

Let's just hope that Nintendo doesn't start releasing a new controller for every type of game...

Meh, it looks like a cheap piece of plastic to me. That's just my opinion though.