Apparently iPhone 5 wouldn't work well with NFC because of the aluminum back plate. That and trying to make it thinner possibly.
So the tradeoff is, a certain form factor design vs. a feature with potential but largely unrealized.
I like the idea of NFC. When I travel to Europe, I run into plenty of situations like gas stations and train station kiosks which won't take my American credit card. If it could rectify those situations and also let me use instead of buying an Oyster card when I visit London, I'd be all for it.
But it's a chicken and egg situation that's not going to resolve itself any time soon. Hell, if Americans can't get EMV credit cards, what hope is there for NFC transactions?
Anyways, I hear there's the potential to use Bluetooth instead of the tech that NFC would use, which is RFID I guess?
If Passbook takes off with iOS6, maybe they can get more companies to participate and build up a network for doing transactions.