(1) Buy Capcom. They're about to go under anyway. It's time to start putting some of those billions to use. I think it's getting to a point where gamers need more exclusive reasons to own a Nintendo home console, and that would be the impetus for most of my decision making. If you want to play Resident Evil, Devil May Cry, Monster Hunter, Mega Man, Street Fighter, Okami, Dragon's Dogma, Viewtiful Joe, Strider, Breath of Fire, Etc., well, you have to buy a Nintendo console.
The buying companies model didn't work like that, chances are workers just jump ship if Capcom is no more, so you finish buying a bunch of IPs without talent to back them up.
(2) Make a strong effort to make the WiiU THE RPG machine. Going back a couple of months, I would have bought Atlus. It's a genre that still has a sizable, and worthwhile fan base (especially in Japan). Having Monolith Soft (X) and Atlus (Persona 5) in the stable would be a very nice start, but it certainly wouldn't end there. I'd get Sega on the move with Skies of Arcadia 2, commission Konami to work on Suikoden 6, get localization deals on Namco's Tales of series, get Level-5 thinking about another Dark Cloud game, make another Shadow Hearts or Tactics Ogre possible, etc.
I think they have more agreements with Atlus, since they are co-developing FExSMT, they have good relationship with Level-5 so a co-developed game would be nice, Namco's Tales is a little harder though, since most of the fanbase is on PlayStation, although Nintendo would work in make the serie bigger in Americas as they did with ToS.
(3) I would approach Square Enix to fully fund a Final Fantasy 7 remake AND a new Final Fantasy Tactics for the WiiU. Also ask for a Kingdom Hearts 3 port, even if they have to pay for it themselves. It's bad that a major game like that is skipping the Wii U.
It would require a big effort from Nintendo's side convince SE, because SE seems strongly moving towards smartphones.
(4) Find high-end developers to work on new sports franchises for the WiiU. This would be taking a page from the Sega handbook on what to do when EA wants no part of you.
Nintendo is already leaving a bunch outside companies handling its own titles, once they can find the balance to make HD development less stressful they would work in new games-ips, as now they are struggling to get its own titles out.
(5) Get Gamefreak to work on that Wii U Pokemon game that every fan has wanted for years, but hasn't gotten yet. There isn't a better time than now to make that happen already. I don't care if it's just a follow up to colosseum/XD. Just give us something.
A port like MH3G-MH3U would be nice, giving bonus to people that have the 3DS version for playing the Wii U version.
(6) Make F-Zero, Star Fox, Metroid, Earthbound, and Kid Icarus on the WiiU happen, while taking a 2 year break on anything Mario. Let's bring other Nintendo IP to the forefront for a few years. If a break isn't possible, then I'd be okay with them keep making mario games as long as it doesn't take away resources from different games.
I agree, we got too many Mario games, I think the serie need a little rest. StarFox!!!! PLZ!
(7) Market the hell out of just about everything that's going on and coming out.
Nintendo has been quite shy on marketing Wii U, even great features like remote play gets ignored. Nintendo Directs are nice and all but its reach is rather small due it only targets the hardcore Nintendo fan. I said marketing the VC, remote play, they have these great features but Joe average have no idea about them.