Annual!?
They release them in one game per generation, even Mario 3D game (with Wii expectation) is one game per generation.

Only franchise that become annual for Nintendo is Pokemon.

Really the reason I'm always so excited for another nintendo console is I know I'll almost certainly get another installment of a main 3d Mario bros, mario kart, super smash bros, and zelda title... It's like a once or twice every half decade treat that I look forward to.

I can easily see some burnout if they were to simply release slightly modified versions of their games every year like a Madden/CoD/Assassin's Creed etc.

I dont like annual releases with no improvements like FIFA
What Nintendo does is the best way

I love this philosophy, Nintendo kinda feels like they are on a whole another level at making games, its just not making games like any other dev. Its having some unique to it. An example of this, after xenoblade chronicles was released on Wii, nintendo decided to buy monolith soft quick before anyoone else takes this amazing developer.

And I'm perfectly OK with that! I really can't imagine a world where Mario Kart and Smash would be annual releases. There would be a huge lack of hype for both of them, specially Smash.

As Nintendo combines their handheld and console, expect all their franchises to happen at least twice per generation.

No, not at all. A Mario series has never gotten an annual release.  There are multiple, seperate teams at Nintendo that are in charge of different types of Mario games.  The only similarity being that the Mario character is in them.

Pokemon as a brand may see nearly an annual release, but it's the same deal there.  There's Mystery Dungeon, eShop spin-offs, and remakes in between main entries in the core series.  There are at least two years in between main Pokemon core released, and usually three.  As with Mario, there hasn't been a full 3D release since 2013.

Annual releases kill any interest in a franchise among the gaming community. Wait is good.

It's like when you were a kid, your parents would take you once in a while to the movies so it would make the experience more intense. Then, when you grow up, you start going there more often because you can now pay by yourself, and the experience is much less engaging.

Doubt it, you'll just see those games supported by more dlc, I'm talking about Smash and Mario Kart here. They really don't need two games per generation.

Hopefully it would lead to an increase of good Zelda games yes.

I said this years ago ( http://gamrconnect.vgchartz.com/thread.php?id=181277&page=1 ) , and talked about how franchises like Mass Effect and Call of Duty would also reach legendary status if only one (or two) entries came out each gen.
Its not magic, its perceived value. If a game comes out every year people think less of it, regardless of its quality. If a game is multi-plat, same thing. "OMG its also on PC" third party games would be treated like the second coming if they became truly platform exclusive too.
That's why Nintendo (and its fans) hate the concept of going third party because then the IPs perceived value would go down and they wouldn't be able to make bold and ridiculous claims online.