The GBA sold 80 million LTD despite having its generation cut fairly short, it almost certainly would've topped 100 million otherwise.
The 3DS will probably stall out at 75-80 million, that's how its looking right now. That's pretty decent, but it's also lower than what Nintendo's sold since like the 1990s.
The lack of year over year momentum for the 3DS indicates smartphones/tablets are spreading like a cancer more and more every year, Nintendo is fighting like crazy to try and ward it off, but 2014 is going to be the year where their lineup is a little weaker because they have to give the Wii U some support. Tough situation for Nintendo.
I think what's happening is every time Apple or one of the big Android manufacturers (Samsung) releases a big new phone or tablet, they end up getting some new customers each time, and those tablets/phones even if they belong to parents are ending up in the hands of their kids too.
It's like Nintendo is on a boat, they plug one hole but as soon as they do another two pop up. That's why the 3DS doesn't look like it has any momentuem even with things like Animal Crossing, Monster Hunter 4, Pokemon X/Y, 2DS release, etc. which in the past probably would have created larger increases for them. Now they need this just to tread water.
