Most cameras are not designed to be any more modular than switching a lens out. They are next to impossible to user-service or upgrade, and if you want to use a different lens system and there isn't an adapter...too bad. That's where Korean designers Dae jin Ahn and Chun hyun Park come in. Their modular camera concept envisions a future where the user can upgrade or completely change key aspects of their system with ease.
The system is called Equinox and it's based on the square core you see pictured below.
Each "core" is made up of a specific sensor and mount pairing and allows you to attach a variety of bodies to it. As it stands the concept shows three different body styles. From a barebones grip and viewfinder to a more familiar body that allows for full manual controls. They have even fleshed out an idea for a studio base that tethers (pictured below).
Overall I think this is a fantastic concept however unlikely it is to actually be produced. There are some things I would love to see fleshed out more, like battery and card compatability, as well as viewfinder or LCD options for the more robust body styles. There are some problems to consider too...my first thought on seeing the studio rig was how fragile it looked having all that weight on a small sensor unit.
All great things start as a small idea and I'm really hoping this one gains traction as time goes on.