@byterunner: I know you didn't see it, but in my edit I talked about a slide that shows the wii u and 3ds coexisting with the NX. Seems like it's a new category of hardware
In the Q&A at the end, when asked about timeframe for release of the mobile games, Iwata said he doesn't have anything to announce right now but that he doesn't see the advantage of the collaboration if they're not able to release something this year. Development will be handled by both Nintendo and DeNA, with Nintendo doing most user experience work and DeNA will do more backend analysis and server work. Sounds like Nintendo develops the games and sends them to DeNA to get them working. He was also adamant that the mobile games will not just be 3DS ports, due to needing the games to be tailored to the mobile platform. Iwata is definitely saying the right things here, hopefully it pans out.
The way Iwata was talking about the NX, it sounds like the NX will be their next generation of dedicated gaming hardware (IE: Console)