According with a patent filed by Nikon, the company is working on a camera with interchangeable sensor
A patent filing in Japan reveals work made by Nikon on a camera with interchangeable image sensor, an invention that would allow a digital camera to last longer, to be upgraded and even to get transformed into a superior class device.
A single camera body, more image sensors
Digital cameras these days act somehow as miniature computers, they have hardware and software and, while the software may be changed in the form of firmware updates provided by the camera manufacturers or custom firmware provided by 3-rd parties (one such case is Magic Lantern for Canon devices), the ability to change the hardware is limited to the lens.
A very important element in the construction of any camera is the image sensor: it dictates the ability to capture images and their quality. Patent 2013-187834 filed by Nikon in Japan proposes a camera design with the ability to change the sensor.
A relevant quote from the patent application says: “Conventionally, there is a digital camera provided with a removable image sensor unit to a camera body. In such a digital camera, an image sensor unit is interlocked with a camera body by electronic contact including an image sensor and its peripheral circuit.” (source: Japan patent database)
Upgrading the sensor makes for an almost new device
As one can upgrade his PC by replacing the CPU with a more powerful one, an interchangeable sensor in a digital camera would allow for a somewhat similar upgrade: transform an APS-C camera in a Full Frame by replacing its sensor or transform a Full Frame into a Medium Format by replacing the sensor. The combinations could be limitless: the solid Magnesium body of a DSLR, while keeping the price under control with a lower priced APS-C sensor, or the other way, a more powerful FF sensor on a lower priced body.
There are also implications on the life duration of a camera: the solid body lasts longer, while the image sensor gets morally obsolete, replacing it with a new model would be like getting most of the features of a new camera model at a fraction of the price.
However, a patent application is only a patent application, development of an actual product may take long or the product may never see the light of the day. It is worth noting that Nikon has already filed a couple more of similar patents in the past.