Schwan: There's only a small handful of apps supporting Passbook right now. We're going to need to see broader support from application providers. It's not trivial: There's a server-side component to exposing that service, as well as the client-side on the phone component.

The other thing about passes is that they can't be dynamic. In order to fully expose the capability and make passes contextual, it requires a bit of engineering. It's going to take enterprise app developers a little bit of time to fully set their strategy and build out support. Frankly, most folks are a little behind.

With Passbook and NFC, retailers are in a tough spot. Isn't it too early to embrace Passport?

Schwan: There's a war happening right now in the mobile payment space. Different solutions are coming out. A lot of the retailers are kind of hanging back and watching before lining their chips up behind a particular solution.

The nice thing about Passbook is that you don't have to say, "This is going to be our mobile payment solution." You can experiment by adopting it as a platform for gift cards, coupon redemption, or deal delivery. You can still dip your toe in the water with Passbook while you're waiting for the overall payments war to shake out.