An Apple patent recently published by the US Trademark and Patent Office shows a removable back that may contain interchangeable optics for the camera. It's unclear whether this patent would apply to either an iPhone, iPod touch, or different device yet to be released but it's a strong deviation from Apple's current strategy.
This particular patent suggests allowing more options for optics including better zoom capabilities, better shutter control, removable close-up lenses and IR cut-off filters, the addition of motion sensors, flashes, and more.
While the iPhone 4S already has a great camera, many accessory manufacturers have taken advantage of that and introduced add-on hardware such as the Olloclip. It's probably only a matter of time before Apple will choose to take advantage of the huge market for camera add-ons as well and their solution may be removable optics:
A portable electronic device includes a digital imaging subsystem with a lens having an optical axis. A case encloses and supports the digital imaging subsystem in a first defined positional relationship to the case. A removable panel is coupled to the case and held in a second defined positional relationship to the case that covers the digital imaging subsystem without the removable panel being directly connected to the digital imaging subsystem. An optical component is supported by the removable panel such that the optical component is aligned with the optical axis and alters optical characteristics of the digital imaging subsystem. The device may include a power supply and an electronic control system coupled to the digital imaging subsystem and the power supply enclosed in and supported by the case. Electrical connectors may couple the power supply and the electronic control system to an electrical component on the removable panel.
There's only so much you can squeeze into a singular camera in a smartphone before you quickly hit limitations for low light, motion blur, and other issues that arise without the use of lenses that are tailored to handle those kinds of situations. Buying optic add-ons could be a solution and potentially a huge market for Apple.
Anyone think this is anything Apple would ever implement in the iPhone?