You don't get a 10% discount, you get a 10% rebate and can only redeem the points when you get to 500 points (i.e. once u have bought $50 worth of digital games).
Same difference. I get 10% back towards a future purchase, and considering that lots of games will be made available digitally, I might opt to not get a physical copy in order to "save" 10% (I'm also sure there will be plenty of DLC for games such as NSMBU and WiiFit U that I will feel obligated to buy)
But I didn't realize that you had to save up 500 points to redeem....