Ah, yes, rereading it, that does seem to be the case ("2GB max at launch").
Personally, I think having two gigabytes as the absolute minimum card size would have been better; as seen with DS games, developers don't have to use all of that space, and untrimmed ROMs for every single game being a minimum of two gigabytes would put a damper on piracy (if not due to pirates having to download the ROMs, then due to not having space on a microSD card for a lot of them). I don't know if the larger cards are more expensive to manufacture or anything like that, though.