Hardware wise, i think that Japan is a bit low, even with the earthquake, as other platforms are selling like they normally did before that.
It`s the software numbers that are really hard to understand. 15 million is a lot of shipped games for a period of one month and a couple of days.
Hardware outselling software is funny but only proves that some people either didn`t care for the launch games or were just happy with the built-in software. If the last one is true, Nintendo made the right move in including them with 3DS.