Slowly but surely, developers are starting to incorporate Apple's new Passbook feature into their mobile apps.
The new feature allows iPhone owners to have all their tickets and discount coupons in one area. Unlike the Newsstand, the updated app does not move into the new area but stays as a stand-alone app.
From the American Airlines app description:
For Passbook users, you can add your mobile boarding pass to Passbook and it will automatically appear on your lock screen as you get closer to your departure time. You can find out additional details about your flight by selecting the information button on the front of your pass in Passbook. This information button will display your record locator, departure date, duration of the flight, and if wifi is available for your flight. The pass will automatically update with flight details if flight status is checked in our app.The new Passbook feature was introduced with the launch of iOS 6 and was, along with the new Maps, the big app changes introduced with the OS update (the camera app also contains a new feature, Panorama).
Passbook, while part of iOS 6, is not included in the iPad version of the software.