Originally Posted by dragonyeuw
I think the dual-screen novelty was a contributing factor in the original DS's success, a novelty that's no longer in effect with the 3Ds. I think 3Ds will do fine as well, but likely not DS numbers. As much as some don't want to admit, IOS/Android will be a big factor going forward and I think the Vita will make some noise as well. A Nintendo machine is the only place you'll find Mario and Zelda though, as long as those properties remain viable Nintendo will always be 'in the game.'
Actually, it was the touch-screen that was the real selling point. The dual-screens was nice and all, but that wasn't what really intrigued people, IMHO. Folks forget that the DS was released before the iPhone and was the first mass device to feature a responsive touch-screen like that.
There's no question that the Android and iOS markets are a competitor, now. But I also think that Nintendo understands that (as does Sony, to a lesser extent). The games that will really seal the deal are the experiences a phone game can't deliver or can't deliver as well as the portables. I think another factor is that the 3DS is not tied to a service, has reverse-compatability with the best-selling console in the last decade and is much more durable than the average phone.
I have yet to see a game with the depth of a Zelda or Shin Megami Tensei on an iPhone game. I doubt we'll see something to rival Uncharted of the Vita on the android platform (though the appearance of Minecraft on Android will be VERY interesting). The announcement of stuff like Monster Hunter 3G and Monster Hunter 4 are cementing the DS position in Japan, which in turn will lead to more development.
The 3DS isn't likely to fail...but it is unlikely to reach anything like the success of the original DS. That ship has sailed. The market has changed since 2004 and competition is much stiffer, now.