With a bigger screen and even with a larger battery, Apple could offer an even thinner chassis and probably tapered edges like the iPads have, allowing it to fit in most pockets as the Samsung Galaxy S3 does.
It does make for a device that's easy to hold in one hand securely, with no worries about it slipping and falling, but it lacks the premium look and feel of the tapered carbon-fiber back on the 9900, and even the faux leather on the 9700.