Apple has filed trademark motions on a number of its official app icons, and none of them are new (though the trademarks for the iDisk app and the MobileMe gallery app threw me a bit, not having MobileMe myself). Apple appears to be shoring up its official iPad and iPhone app icon library, and trademarking all of the official icons that it's put together.
Each icon is marked not only by description (the Camera app icon is described as "rounded corners depicting a stylized camera lens"), but by its colors as well, which is standard for a logo trademark. It's also interesting that all of these icons are submitted at a gigantic size of 955x955 pixels, but iPhone icons are shown at 57x57, and iPad icons are displayed at 72x72. Clearly, though, Apple makes its icons Texas-sized and then scales them down to display them.