Take all your standard TinyDuino boards and offer a version that has horizontal connections in place of the stackable connectors.  Not much design change, just a connector change.
This designs that have more flexibility in the horizontal plane to use it but require very thin designs.  Certain designs may not be able to accomodate the thickness of 3 or 4 stacked modules.

Take all your standard TinyDuino boards and offer a version that has horizontal connections in place of the stackable connectors.  Not much design change, just a connector change.
This designs that have more flexibility in the horizontal plane to use it but require very thin designs.  Certain designs may not be able to accomodate the thickness of 3 or 4 stacked modules.

I agree - or create a flat ribbon cable with the Tiny-Duino sockets at each end so the boards can be laid and oriented horizontally in certain designs/projects.