I'm with Pale on this one. To navigate a menu, all you need is either a joystick or d-pad, and at least one button. But, to play ALL Nintendo consoles on one controller, you're going to need a whole lot more than that. Combine the buttons of every Nintendo controller gen and what do you get? A d-pad (every gen), a start button (every gen) a select button (NES, SNES), two shoulder buttons (SNES, N64, GC), an analog stick (N64, GC), a Z trigger (N64, GC), SIX face buttons (N64) and a C-Stick (GC). That's effing MASSIVE. And no you can't always map the c-buttons to the c-stick, or else how would you play KI Gold?
To possibly cut down on this I'm guessing MAYBE the Rev controller won't have something that GC does, but I have no idea what they could remove since all it's buttons are pretty integral. Either that or the Rev controller will be very uncomfortable to play GC games with, or else why would they include GC ports at all?
I'm totally prepared for something INSANE.