The big issue is - can you remain compatible with the arduino libs ? because if not, between the arduino and the mbed ,i'm not sure you could offer much value.

The big issue is - can you remain compatible with the arduino libs ? because if not, between the arduino and the mbed ,i'm not sure you could offer much value. As for multithreading,debugging and events i've already seen an arduino debugger, easy to use rtos and maybe even easy to use event system. The problem might be mostly marketing ,not development. But i could be wrong.