Lets say GHI offered a module specifically made to control LEDs (Don’t we all love LEDs!) where the module took SPI from the mainboard and gave you digital output (shift register basically) then how many IOs will be too many? Do you see yourself using 100 outputs, 200…1000!!! The outputs are rated 20mA so standard LEDs can be wired directly but you will need transistor to wire large LEDs.
Remember that you will be wiring each LED so keep that in mind when you give a number back. Also, note that you can wire things in a matrix form and now 16 pins will give you 8*8 LEDs 64.
LED cube anyone?
Time to remake this using gadgeteer