Use a strategy the opposite of the Wii U and almost the same as the Wii. They had good, memorable TV spots for the Wii and lots of them. The Wii U was abyssmal. The Wii U actually had a better line up when it was released than the Wii, but it didn't have any must have games like Wii Sports (likely a phenomena that might not happen again) but could be challenged by a really solid genre inclusive line up.
Something that Nintendo needs to do is make an action adventure game that is accessible to more age groups as well. Something along the lines of Uncharted and Tomb Raider. That's a genre that is almost completely missing from Nintendo and it's fairly popular.
Lastly, they need to attempt to get third party support... again... Make a system that is beefy enough to run the same games as the competing consoles and is easy to develop for. The easier the better, that way it isn't necessary to have a long porting process so the risk/reward involved works out more in the third parties benefit.
Gotta figure out how to set these up lol.
