Hey everyone!
I've spent the last year developing two new boards based on the Microchip SAMC21. They are intended as drop-in replacements for the Arduino Uno and Arduino Mega. They run at 5V, have an ARM Cortex-M0+ core, a rich peripheral set including dual CAN controllers, etc.
I've just released these boards on Tindie. You can also check out the hackaday projects link. The documentation is linked in both sites.