Alright, so people don't want to read information apparently. Well it's spread out, who can blame them. So here it is:
Here's the main controller:
Pretty obvious generally. What you can't see is that it can detect movement. As Reggie explains:
You can also turn the controller on it's side for a very quick and easy NES controller.
The bottom is an expansion port. This is essential for understanding why it can play half those games you think it can't. More later.
The first and likely main use of the expansion port is for an analogue stick attachment:
What you can't see in this pic is the two triggers below the stick. According to Iwatat's speech, Nintendo plan to pack this attachment in with the system.
With the analogue stick attachment, the Revolution controller has as many buttons easily to hand as a Dual Shock minus the D pad.
For an idea of the size:
That's not the only expansion though. The one we know of makes the controller work for traditional games. Yes, even though for many genres the normal set up doesn't hinder things anyway, Nintendo are still providing a normal controller feel. From Iwata's speech:
What other expansions are to come? Who knows? The good thing about the expansions though is that it can allow so many different games. Worried about your fighters? A 6 button (or whatever) expansion removes all that worry, assuming you're not using an arcade stick anyway.
So is it true that the new set up will make a few genres great and screw the others? Not even close (unless I mention it, I'm talking about the normal controller and analogue stick combo, not even the classic style expansion controller mentioned above):
RPGs - Not a problem.
FPSs - Better than ever.
RTSs - Better than ever.
Fighters - Problem. Easily solved by releasing an add on with face buttons (as many as the game needs, shoulder buttons if it wants it) OR using the classic style expansion controller OR using the arcade sticks you guys seem to love anyway
Platformers - Not a problem.
Racers - Not a problem/better than ever.
Action/adventure - Better than ever.
Flight games - Better than ever.
Puzzlers - Not a problem.
God games/puppy sims - Better than ever.
Music games - Probably needs an extra peripheral but always has. A game like Samba however, you'd just need two normal Revolution controllers.
Party - Not a problem.
Sports - Well...you tell me. Don't play them much. If they'd work, fine. If not, one of these solutions will work. Either a different expansion, or the classic style expansion controller.
Extreme sports - Like the above, except given the Revolution's ability to detect tilt and things, could be better than ever.
Shmups - Not a problem.
I am of course talking in console terms, not PC.
I think that clears up most of the confusion. If anyone suggests anything else, I'll edit.