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I was thinking that a stepper motor controller "cartridge board" that plugs into a board containing other logic could make a lot of sense and be very useful for the DIY 3d Printer or DIY CNC Mill groups. "Base" board here: http://www.circuits.io/circuits/4733 (eventually)
I ended up rebuilding 90% of the circuit after replacing the A4982 device with one that had a slightly better representation. Board design is loosely based on the datasheet recommendations.
The extended pad ground on the top layer can be exposed and used with an SMD heatsink, or another TSSOP compatible heatsink can be used. The board orientation is expected to operate vertically as shown, so un-fanned airflow with or without heatsink will pull heat up and away from the board. A fan would be a good idea pulling air up from the boards, or blowing from (as shown here) left to right. The point is that there is NOT enough copper area for sinking heat if the driver is used near it's limits, plan for additional heat dispersion. The base board will accept larger boards as long as the pins match, so forking and extending the heat/ground plane, possibly adding top-layer heat/ground plane, would be acceptable, however board cost increases with board size. The design specifications outline about 4 times the copper area than is available on this board.
The "two" devices at the bottom of the board are just 1x8 standard 0.1" pin header holes, I was too lazy to build a new part to include. These should be 90-degree headers pointing down (relative to how the board displays here). The right-side header is planned as a screw-in terminal block style connection.
The pins, from left to right, are Vlogic(5v), !Enable, MicroStep1, MicroStep2, Step, Dir, Ground, and Vmotor.
Thanks to Benjamin Schrauwen for the head start. :-)