Increase in smartphones is a reason.
However a big reason that people often overlook is that the DS only blew up in sales with the Lite + Mario + Brain age and a ton of more 'casual' stuff.
I think we need to wait and see how the 3DS does once it gets 2D mario, 3DS XL and some of the more casual things.
TBH I don't expect it will manage to do as well as the DS. I have said it before but the DS+PSP generation wasn't the normal. It was basically the perfect time for handhelds. However 3DS can still do very well in the West. Just wait a few months to see what happens.







