Motorola seems to be getting pretty serious about open hardware after being acquired by Google - it has just announced Project Ara.
We want to do for hardware what the Android platform has done for software: create a vibrant third-party developer ecosystem, lower the barriers to entry, increase the pace of innovation, and substantially compress development timelines.
The design for Project Ara consists of what we call an endoskeleton (endo) and modules. The endo is the structural frame that holds all the modules in place. A module can be anything, from a new application processor to a new display or keyboard, an extra battery, a pulse oximeter--or something not yet thought of!
This might sound similar to a recent concept proposed by Phonebloks - indeed Motorola is actively engaging that global community to develop this.