I think Nintendo needs to focus on growing as a first party and heavily increase the number of second parties, and instead of trying to cater to third parties, they should be focusing on increasing the number of second parties they have - and build them up to be superior to the third parties.
Getting companies like Monolithsoft is a great way to expand and diversify. They should also start trying to clinch markets: they should try to gain Level 5, NIS, and Marvelous as a second party and clinch the RPG market. Square/Enix would be a good but unrealistic acquisition as well - but Nintendo should either get them as a second party or pump up Monolithsoft to out-compete Square-Enix. Although, personally, I think getting Square Enix as an exclusive developer would be the clinch they need to secure the RPG crowd since then pretty much all of the best RPGs will be on Nintendo systems exclusively.
They also need to start invading American territories and start picking up strength among the lower brow gamers who play Sports, racing simulators, and First Person Shooting titles. The key to this market is generally licenses, so Nintendo will have to get some good licensing for these types of games.
At the same time, Nintendo needs to start blowing up on the marketing front by using the Miiverse, if this was as visible as Twitter or Facebook, they would get much more exposure. Nintendo also needs to actually start showing people games that are in development, rather than being so secretive. Secrecy doesn't entice people unless you have an established clinch on the market.
I describe myself as a little dose of toxic masculinity.
