I'll bring my 250mm-sized quad copter to EMF; shouldn't be very difficult to replace the controller board with the MKe. If you don't mind not having stabilisation (horizon mode) you can put it together with four PWM outputs and one digital input.
The badge is running FreeRTOS, and has a custom-written screen driver. It also has the ability to run tasks that have been built using the normal Arduino IDE with a special build target!
If everything goes to plan, we'll have OTA code loading and a really basic "App Store"...