The Android counter response is always so predicable. "Big deal, I do that already!...at home by myself...with virtually no software support..." I mean, seriously, juggling a Wiimote and a phone at the same time...not exactly elegant. You do that to work and back on the bus every day, right? The fact that range concerns you shows how much you are missing the point. Both the controller and the phone would be IN YOUR HAND. How much range do you need for that?
Don't get me wrong, being able to use the Wiimote for anything non-Wii has tremendous possibilities, but its not exactly a great package for gaming. The Wiimote, by its very nature, leaves a lot to be desired gaming controller-wise.
The reason why this could be great is pretty damned obvious. As it is, the iOS is a very significant gaming platform, but at the same time is, for me, almost impossible to enjoy gaming with due to it being touch only. While there are things like that iArcade controller (which only works with a very small number of games and it also stupid) and some Jailbreak-only things, they only addresss a microscopic sliver of users. Nobody is going to develop Metal Gear Solid, or Super Robot Wars, or Formula 1 2012, or Phantasy Star Online for a controller that only %0.001 of all users have access too.
NFC works perfectly well enough for a controller-shaped dock that the phone physically fits into. If its 1st party and contains a good d-pad and a few buttons it will INSTANTLY transform mobile gaming because EVERY game released will support it. Since there are dozens of games released every day for iOS this would be a big deal. Over and over again I'm elated and then disappointed by iOS games. I see the thing, it looks rad, then I'm disappointed when I realize that I almost always abandon virtually every iOS game because they are touch only.
If they make such a device...Nintendo and Sony are f*cked. Well, Nintendo would probably be fine, but an iPhone 5 with a real gaming interface would basically single handedly kill the already struggling Vita...instantly. Developers would start making real games that are worth more than $0.99 for the iPhone and there would be no point in doing anything for the Vita (a system that few companies are doing much for already).
Overall...I'm not so sure this thing will happen, or if it does that it will be handled well. Its not a small thing though. If done right, it will be a big big deal. We can't count on that though. Apple makes the best track pads in the world by far, but they make mice that are absolutely SHITE and seem to not be aware of it at all. They might do something stupid like put a Sidewinder style diagonal D-pad on it, make it one button, etc, there are a million ways to f*ck up a controller.