Has anyone mentioned the fact that music/video stores sell iTunes cards? They don't usually sell iPod/iPads at those places either, as Apple has severe restrictions on how their products are displayed/sold.
A $10 iTunes card costs $10. I wonder if the store makes any profit at all on those things?
Also I think this price discrepancy will filter out over time, plus you have to give it to Nintendo, they're the only ones trying to gently ease (ahem) "normal" people into buying digitally. How many of your Aunties/Grandparents gifted you a game on Steam or PSN? Over the next few years we could be seeing every game have a box and d/l card side-by-side, with a few dollars difference (hopefully the correct way by then!).
It may suck a bit now, but things can only get better. Hopefully.