Today it takes up to 23 pins (top) on an SoC to manage all the MEMS sensors attached, but by drafting a universal interface, the MIPI Alliance hopes to reduce the required pins (click on image to expand).
Source: MIPI Alliance
Here is what EETimes says about a sensor interface standard: A standards development group is exploring the feasibility of a new interface standard that would enable even multiple degree-of-freedom arrays of micro-electro-mechanical system (MEMS) sensors to use a simple common interface.
Such an interface—which would be used by accelerometers, magnetometers, gyroscopes, altimeters, compasses, proximity sensors and non-MEMS sensors like GPS, near field communication, fingerprint identification, and the touchscreen itself—would require agreement from all interested parties on what protocols need to be recognized, according to the MIPI Alliance. The organization recently announced an open "birds of a feather" group to investigate the requirements for integrating multiple sensors into mobile systems...