hello i'm a hardware and software libre developer and advocate, currently living in Taiwan, and in looking to create a low-cost high-performance 3D printer board i could not find a low-cost arduino 32-bit board to go with it... so i decided to make one. it's been named the "STL47o" - ST El Four Seven-oh....
with the help of the stm32duino.com and arduino.cc com communities the STM32L471 was selected, and the STM32F070 chosen to provide firmware (DFU) management, and USB-UART connectivity.
some care was taken in component selection to ensure that the board will be low-cost, starting from the Arduino Reference Design (0805 components) instead of the Due Reference Design (much higher cost and uses 0402 components). it's an open GPLv3+ licensed design, i've just sent off for 10 PCBs and sets of components, i'll be doing the initial assembly myself, and have also asked the factory in Shenzhen to quote for 50 and 200 full assembly.
if anyone is interested or would like to help do make yourself known.