I've been working on a stepper motor driver board. This is somewhat related to the Gen7T. I'm trying to fit the design into a 10cm by 10cm area so that it can be produced inexpensively by iteadstudio. My control board will be another 10cm x 10cm board.
I'm designing the motor controller with 6 stepper drivers so that it will be useful for testing multi-extruder configurations. To keep the board size down, I'm dropping the normal jumper configuration in favor of a SPI GPIO expander.
Much like with the clarky and bryanandaimee solutions, I was forced to drop the fuses because of routing space and board area.
The stepper motor drivers are paired because of the GPIO expanders. I have a power switch which is in a different schematic.
Here's the schematic
