I've overthrown the selected EOMA68 cpu module for my laptop and I am currently designing something completely own/new. The new system will be completely modular, which means that any part of the hardware (except for the body) will be exchangeable. I will plan the whole system and put anything under some Creative Commons license.
The mainboard and the chassis itself will be the only parts which should life forever. I've selected some connector from Samtec for the modules. All modules will get a casing (3D printed is prefered), so they can be carried in your Laptop-Bag. They will be swappable as the pinout of them will be the same for all modules. Hotswap (like USB) will not be supported.The specification of the laptop will look like the following:
CPU Module: Allwinner A20 1GiB RAM Micro SD Card for kernel image Headphone/Mic connector Mainboard: Several USB Hubs Several Module Connectors DC/DC converter for batteryless operation Ethernet module: 1* 1000BaseT 4* 100BaseT (Layer2 Managed switch) Audio module: I2S Audio Codec (to be selected - audiophile needed) Analog surround connectors (5.1) SPDIF I/O over Toslink USB module: 2 - 8 port onboard hub
The connection to the display will be a big chunk of pins which will be routed in a way that you can use RGB-TTL/LVDS/TDMS/eDP over the same pins. There will be a connector on the mainboard which will host a small pcb which will be an converter to the built in display. That means: The display interface will be hard-wired on the CPU card but with some adapter-IC it can be converted. When you change the CPU card in the future you will only need a new adapter PCB and you are ready to go.