Get a FULL Pokemon RPG on the U (no spinoffs) with a large marketing budget. Nintendo should create a new IP that is a fully "Mature" style game and not one that will get abandoned after the first title. Work with 3rd party developers on porting their "New" games to the system; create a team specific to helping getting the ports coded. Create a better system for digital games - have them tied to an account, and not specific to the system. Go overtime on getting more games in the digital space for the Virtual Console.
They also need to put in advertisement how the Wii U isn't an add on for the Wii, but a completely new system - even if they have to use the dreaded "technical" words. 3X more powerful than the Wii, things like that will give people the realization.
