Branching Nintendo games to smartphones would be the worst possible thing Nintendo could do. Right now they make some of the highest quality games. There problem is a marketing problem not a device problem. Games on smartphones couldn't live up to anywhere near their potential. As well they would have to join the horrible trends of micropayments and 99 cent games or ads in games. Luckily I don't think Nintendo will ever do this.
They need to market the Wii U better, its a solid system but there was some confusion about whether it was just a new type of wii or what have you.
They are in my opinion the only console worth buying, (assuming you have a half decent computer). And the only one that keeps gaming on the couch with your friends. That is the heart of nintendo and they have to focus on that.