I still don't get why SD cards wouldn't work for DLC. Let's say each pack is 100MB or so, you could still fit 20 of those suckers on a 2GB card. And if that's not enough, go out and buy another one, rinse, and repeat. Sure it can get expensive, but why not leave that decision up to the buyers?
This is a problem why...?
People have been buying Nintendo consoles for Nintendo games since the N64, and the company's been doing all the better for it. In the end, good games are good games. Complaining that they're all first party is just as inane as complaining all of the good games on 360 or PS3 are third party.