Any chance you will soon offer USBizi on newer ARM single-chip microcontrollers with more memory and faster clocks? I am slavering over the STM32F405RGT6 for example, 1MB ROM, 196KB RAM, 168MHz clock. Since all the extra memory would be available for user programs, this would make an enormous difference to the types of project that could be tackled.
As memory sizes slowly creep up, I am convinced that single-chip is the way to go rather than the Spider/Hydra approach as this keeps the cost down to Arduino levels and also increases the IO counts since pins are not taken by external memory busses.
Maybe even a single-chip Gadgeteer would be feasible?