Progress has been slow on my UxV Control Station project recently due to other obligations. However, I have decided to create an Arduino shield for that project to make it easier for interested people to recreate the UxV-CS. I'm not very experienced in hardware design, so things are going slow but steady.
I will not be selling any hardware but I will publish the design files under a CC license when ready.
Why a shield instead of a full custom PCB? That's pretty easy to answer - it's more flexible. The user can use a MEGA1280 or MEGA2560 or any pin-compatible clone. It's also more future-safe. My current design is just planned for 5V but with very little changes it could be made compatible e.g. with an Arduino DUE which has considerably more processing power.