Yes, but there's also a risk of them not having a business.

Considered the install base of Android + iOS vs. Nintendo portables (or even consoles)?

There's only one rule in Cannibal Club: Cannibalise yourself.

Unfortunately, they might not have a choice in the matter—hardware development is becoming more and more expensive, and I'm not sure Nintendo has deep enough pockets to keep up. Their common tactic of underpowered hardware that's cheaper to manufacture and develop for hasn't really worked out with the WiiU. So it might be, no profits, or smaller profits.

I wouldn't worry too much about "stable", though. Nintendo knows how to sell their software.

How? The 3DS is doing pretty well...

(Risk is not about now, it's about next.)

The article states that the titles on the mobile devices will not be ports of existing games, so it looks like it will be accessory applications like the PokeWalker

It's not that surprising. There is precedent. Nintendo has licensed their characters to other platforms before("Mario teaches typing" anyone?). It's just that those games were never really the same type of games, and of the same quality. I can see Nintendo having free-to-play offshoots of Mario, Zelda and whatever else.

I don't see them releasing first-party AAA titles on smartphones.

What are they up to now? Certainly not leading photography market.

Kodak seems a poor comparison.

They'd get my money either way. Nostalgia is a great marketing tool.

1) Open the eShop

2) Find a game (tons of features sections, look by category/rating/genre, or search)

3) Tap purchase

4) Add funds if necessary, just a tap or two to use your existing credit card details

5) Purchase

6) Download immediately, or put your 3DS into sleep mode and it'll download hands-free

The only real problem is Nintendo's system for transferring to new devices.