I thought the 3DS was a sure bet for Japan. Everyone there has a DS product, so why not the souped up 3D version? The launch of Nintendo's 3D portable was successful in Japan, but sales have since tapered off. On average, the PSP performs better in sales each week.
A new survey by Goo Research says that the high price of the system may be responsible for the slow sales. The top reason given by the 1,000+ people surveyed is that the price of the 3DS is too high and/or that they're waiting for a price drop. I hear the same kind of responses here in North America from those that haven't bought a 3DS yet. It's either the price or the weak launch game selection.
The two other top answers, translated by Andriasang, are also interesting. The second highest response says that the polled people are satisfied with their DS or DSi right now. The third and fourth top responses are health related. It seems that gamers are still concerned about eye strain and motion sickness from the 3D screens of the 3DS.
I think the system is a bit expensive, but I'm also thinking that more Japanese gamers will overlook the price with godo games. Those will come, and I bet the 3DS will be just as popular as the DS/DSi is now.