[citation][nom]nottheking[/nom]That's because a smartphone, while a cool idea, is a VERY ambitious project. You have to worry about a ton more things with it, especially how it'll work with each of the mish-mash of standards any ONE carrier will use on their networks, let alone all of them, plus you have to deal with them, the FCC, etc. about approving its use as a phone, getting a carrier to agree to use it for their customers, etc.While with a handheld console, Nintendo has 100% control; they don't have to talk with anyone else about it, so they have far less things to juggle; it's much easier.[/citation]
I don't agree with that nottheking. Sure, there's more to worry about, but if Nintendo had a similar model to Apple, then it wouldn't be such a big deal. Considering Nintendo's market, they could easily make a deal with a service provider (or several) to have an Apple-like app store and control over their product.
The thing is, they wouldn't.
No matter what happens, Nintendo isn't interested in making a phone, which may or may not be a good thing. They want to focus on an entertainment device, strictly for entertainment purposes. Now, if they made the 3DS have an exceptional camera and made good use of it for gaming, that would be a reasonable exception (as we've stated in this and the prior DS review, the camera stinks, except when viewing on the DS itself).
However, there are possible gaming applications for phones as well, which Nintendo could explore. My impression is that until either Apple, Sony (with their recently-rumored PSP-phone) can achieve great success on a phone-portable console, they won't do it. There's no reason for them to do it, and the aim for an inexpensive portable gaming device and a cheap phone is more consumer-friendly than an all-in-one and expensive device.