Notice that the port to the STM32F103, one of ST's biggest ARM-Cortex-M3 chips, uses most of the RAM and EPROM, allowing only "a small application" to fit. When we see ARM-Cortex SOCs with gigabytes of EPROM and RAM, these Microsoft .NET frameworks may eventually be practical. For now, FreeRTOS and GNU C/C++ is the best bet.
I'm skeptical of the need for this tool. Please, sombody convince me why this might be better than the presently popular C/C++ methods and tools.
When I see anyting smelling of Microsoft coming near resource limited microcontrollers, I start to shudder.