Well if there was any confusion, Iwata just cleared this up in a interview with Time Magazine:

http://time.com/3748920/nintendo-mobile-games/?xid=tcoshare

"Development of smart device games will be mainly done by Nintendo, but it is significant that we are forming a joint development structure with DeNA. Nintendo, through experience in the dedicated game system business, is good at making traditional game products. But for smart devices, in addition to the “product” aspect of a game, the aspect of an ever-evolving “service” is very important—a service that encourages consumers to play every day even for a short time. DeNA has extensive know-how in developing the “service” side of things, and will be primarily responsible for the service-oriented operations. We will be able to greatly leverage strengths of each party."

DeNA will be handling more of the service side/back end stuff, Nintendo will be leading the game development aspect, which is kind of what I suspected. 

Megaton. But its expected. Nintendo wants to be in control whatever is produced using their IPs.

I don't care who makes the game. I just want Elite Beat Agents.

Joking aside, I guess we can look forward to the mobile games not sucking so much.

Oh, I presumed DeNA would be developing the mobile games... interesting. So are they hiring development staff or moving people from developing handheld/homeconsole to mobile..... hopefully the former.

Good. Not saying that other publishers would do terribly with Nintendo's IPs, but, ya know..........this is what Philips did to Zelda so

Ugh. I'm all for this whole move, but the idea of Nintendo's already-spread-thin production teams devoting time to smartphone games and reducing the output of full games even further is just dreadful.

After looking into the sort of stuff DeNA was making for other companies, I have to say thank god.

Nintendo is *very* protective of their IPs, as they are their most valuable assets. So when it comes to game development, there's no doubt that Nintendo will want a hands on approach to ensure that these mobile games ensure that the entire IP (whether it be Mario, WarioWare, Rhythm Heaven, etc.), even outside of the mobile market, is benefited from the mobile game's release.

Another interesting tidbit is Iwata's comments on pricing:

I understand that, unlike the package model for dedicated game systems, the free-to-start type of business model is more widely adopted for games on smart devices, and the free-to-start model will naturally be an option for us to consider. On the other hand, even in the world of smart device apps, the business model continues to change. Accordingly, for each title, we will discuss with DeNA and decide the most appropriate payment method. So, specifically to your question, both can be options, and if a new Nintendo-like invention comes of it, then all the better.

On the other hand, Nintendo does not intend to choose payment methods that may hurt Nintendo’s brand image or our IP, which parents feel comfortable letting their children play with. Also, it’s even more important for us to consider how we can get as many people around the world as possible to play Nintendo smart device apps, rather than to consider which payment system will earn the most money.

Well if NX is indeed a fusion platform where Nintendo's designers no longer how to be seperated into DS/Wii dev teams ... that could free up a new business model

Pillar 1: NX development

New Pillar 2: Smart Device development 

Are they sure Nintendo devs can handle such a dramatic step up in horsepower? I kid, I kid. :D