We don't know exactly when it will arrive, but the next iPhone is likely just around the corner. Amidst speculation about launch dates and incremental hardware upgrades, one question remains. What will be the iPhone 5S's major differentiator?

Since the "S" models are typically incremental upgrades as opposed to a major hardware change, similar to Intel's tick-tock model, they have always included some attempt to establish value through added functionality. The iPhone 3GS came equipped with a new video camera and voice control software and hardware. The iPhone 4S set itself apart with the disruptive Siri application.

A patent application for a physical fingerprint scanner from Apple hinted that they might include a biometric identification system in the 5S, but there hasn't been anything to corroborate that information.

9to5mac calls this the "cool factor," and they think that this year it might come from the camera. Each iPhone since the 3GS has brought new camera and video features to the smartphone, but as iOS 7 has yet to offer any new camera improvements beyond filter effects, it's a suspect area for a big move.

iPhone Model New Camera Features
iPhone 3GS Advanced video recording + Face detection
iPhone 4 720p video recording
iPhone 4S Advanced optics system + 1080p video recording
iPhone 5 Panorama tool
iPhone 5S Mogul?

Hamza Zood discovered a new feature hidden in iOS 7 beta development code called "Mogul," and turned it over to 9to5mac. 9to5 says that through their testing and analysis, it appears that Mogul enables the iPhone to record video at a very high frame rate of 120FPS.

120FPS footage is crisp and clear, and is often presented in a slow-motion state. Apple already has some competition for slow-motion capture in Samsung's Galaxy S4, which has a similar feature.

There is no confirmation that this high-speed capture feature will be included in the next iPhone, but given the lack of other camera enhancements and Apples pattern of upgrades, it does seem likely.