Nope, it definatly does not need to get reprogrammed.
The reason is that even though your buying bigger rims, you'll be getting smaller tires, so that the overall wheel+tire combo will be the same size as stock. As long as the overall size is the same, then the car doesnt notice a difference and the speedo will be on check.
You can actualy use the calculators on the top of the wheel and tire forum to see how much of a difference there will be in the speedo with your new tire setup. Use the boxes on the right to set in a new tire size
For example, I used 19" wheels with my E46 once, and I put on 235/35/19 tires on the wheels, with that setup, according to the calculator, there is only a 1.53% difference, and my speedometer will read 61mph (when im really going 60mph), not enough of a difference to really matter