The OP points out how Nintendo has made some definitely mistakes this last year and needs to correct them going forward but it's a bit presumptuous imo that it means they are doing major shifts such as going heavily into cellphone development or firing Iwata, especially when they just have put their studios in a new building, have just the last few months have mad more shifts in management such as Iwata taking over running NOA, and they are just now hitting a stride with simultaneous Wii U and 3DS development after difficulties adopting HD development. Those are all changes that haven't really been able to be implemented/gain traction well into 2013, so I don't think we've see the benefits of those changes until the end of 2013 (increased game production, increased advertising of the Wii U with a more focused message, potential improved relationships with Western 3rd parties with Iwata learning more about the market and what those publishers/developers might want from Nintendo, etc.)
I know people are getting a little trigger happy with other new consoles having successful launches but IIRC so did the Vita. The sales trends/predictions of the Wii U don't look great but they can improve with more titles coming more frequently with more advertisement (which will be more effective with more software to back the system). The 3rd party situation will continue to be pretty lackluster imo, even with better sales of the console just due to prevailing attitudes in the industry. Short of Nintendo releasing a paradigm shifting game for the system, I don't see much changing any time soon on that front.
I think 2014 will be a more vital year because the Wii U had a headstart and regardless of how poorly Nintendo took advantage of that, they still have a lead despite the strong start of the other consoles meaning they are still in the race despite what others want to claim. 3rd party support seems like it favors the other consoles over the Wii U already but the games aren't there yet. The Wii U is stronger in that regard than people want to give them credit for and if anecdotal evidence is worth anything, it would seem they still had a good December and the Xbox One may have already begun stalling. A lack of 3rd party support might not really hurt their hardware sales until the other consoles have build up an actual, not hypothetical, difference in software support. That means Nintendo has a chance to turn things around like they did with the 3DS.
OP brought up Japan having consistent number but other parts of the world being more important but I'd say downplaying the Wii U having an upturn in the Japanese market is overlooking how much that market can help the system. The 3DS has been successful predominately from being successful in Japan, from getting Japanese developers on board to just having support that can be localized for other parts of the world and with Nintendo increasing their localization efforts to even help 3rd parties localize games, if they had to do the same with the Wii U, it would mean there would be more games for the system. The Wii U might not be as successful in the West if they had mostly 3rd party support from the East, but it would at least help give the Wii U more of identity and therefore a niche to cater to. Nintendo already has build good relationships with most Japanese publishers and if they give them good reasons to support the console and continue to build a rapport with partnerships, it could start some much needed momentum. There already is an opportunity for Nintendo to capitalize on often neglected genres on consoles such as character action, JRPGs, in some ways survival horror these days, etc. Maybe these genres aren't necessarily past their prime, and having one platform that is dedicated to catering to audiences that want to see those games and allow for budgets and business models that make more financial sense than AAA/multiplatform development probably did for those same genres, than maybe the quality that used to be associated with Japanese development can flourish in this modern industry. We know that there are still audiences for these games, they just need to be tapped.
Nintendo it seems has also begun to take a few more chances with their franchises that have been paying off. I think the most obvious example to me is LoZ: ALBW. It rethought conventions, had a smaller team, had a younger director and lots of fresh new ideas, etc. It was a great example of Nintendo sort of trusting these developers they have been grooming for years and seeing them be able to have big success because of it. Nintendo has been sort of slow to do this but they've had success with recognizing someone like Masahiro Sakurai to have lots of talent at an early age. Hopefully they continue to let their developers do more smaller games as well as slightly bigger scale games I think an injection of new ideas could help the game development side more than the managerial side of things since creativity is the name of the game.
Not to mention many indie games being developed for the Wii U aren't hitting until next year. These are all developers that have been on board and in many cases, the sales don't have to be huge to be a success in the way AAA development does. That scale of development benefits greatly from Nintendo's approach in a way it couldn't on the Wii (but should have been able to). People keep saying indie development is the future of the industry and Nintendo has seemingly created a pretty good environment for them to thrive in. It may or it may not be enough to sustain a console due to the price point, but in combination with existing support, it can fill the gaps between big releases nicely. It already has for the 3DS.
In conclusion, there is no need for Nintendo to throw the baby out with the bathwater. We know they need to continue to make necessary changes for the Wii U to be as successful as it can. I think revising their sales estimate for the fiscal year is all but guaranteed, regardless of how well they did in December, but their future isn't only 1st party games and nothing else on the horizon. The have a lot of work to do, but I don't think the console it in danger of having to be discontinued like people think it is.