What device (other then those starting with "i") doesn't have "memory cards" in the last 10 years?
Anyway proprietary cards have been known for nearly a year now, not sure what's with all the surprise. The game-carts have save space, so the expansion is for downloads (which granted, many of us will want, but it's hardly needed for the crowd that was screaming at Sony to support cartridge games for the past 7 years).
Actually my 3DS turned itself off when I charged it for the first time while plugged into power - the battery was draining faster then it could charge :/