We had a chat about this before and since then a stepper module was offered by the community http://wiki.tinyclr.com/index.php?title=Community_Offers Although this is a nice little stepper module, it has its limitations. First, it depends on NETMF for timing (not real time) and second it is not suited fro high power (heat).
After thinking about this for long, this is what I came up with. There are hundreds of stepper motor drivers out there that run off a PC’s parallel-ports. Some have heat sinks, some even have fans. Some companies even sell them with suitable large motors as a set. Even if it is not parallel port, it still uses the same concepts, pulses for steps. I think 90% are based on TB6560 chip from Toshiba. http://www.toshiba.com/taec/components2/Datasheet_Sync//382/27885.pdf
5 axis driver: http://www.aliexpress.com/product-gs/320121980-5-Axis-TB6560-3-5A-stepper-motor-driver-wholesalers.html
3 axis driver: http://www.aliexpress.com/product-gs/320124466-3-Axis-TB6560-Motor-Driver-Stepper-controller-wholesalers.html
one axis non-parallel: I peeked inside our laser machine and this is what it uses! http://www.aliexpress.com/product-fm/493655561-Free-Shipping-3-pieces-lot-24-50V-DC-CNC-Stepper-Motor-Driver-Controller-2M542-4-2A-wholesalers.html
So, instead of limiting our module to a motor type or voltage, I think we will offer a module with parallel-port output. The module will have its own little 50mhz micro to handle timing and keep all motors in sync, which is very important when you are doing a curve. The C# code will send high level commands to the module, like 50 CW steps on A, 30 steps CCW on B. And then other commands for curves.
With this, you can use large or small motors, select the driver that fits your needs and hopefully create a commercial product using gadgeteer. Our laser machine would be MUCH more professional if we upgraded it electronics with FEZ Spider