The thing is, Jim, Nintendo has done this same thing in the past. Sometimes it works, sometimes it doesn't This doesn't sound like a canny and insightful move by Nintendo so much as the occasional stroke of luck by a bunch of people who more or less flail around randomly.
The tablet as a playing screen is a nice one though.
It's also worth noting the slow adoption of new technologies. Smart TVs are the new gimmick which may or may not catch on, but it will be a qhile before their ubiquity threatens Sony and Microsoft even if they do. This makes it highly unlikely that it will be a threat to the upcoming sequels to the PS3 and 360. Case in point, DVD is still the leading physical medium for video, and it took the artificial death of VHS to make it dominant (and then only several years after the fact did it happen). HDTVs, what the current gens from Sony and Microsoft were built around, are just now getting to a reasonable saturation point. New gadgets may not be enoough to push these TVs, especially with an embedded userbase of Sony and Microsoft fanboys and fangirls.
Not that I particularly want to defend Microsoft's practices of putting social media and stuff ahead of gaming, but these days anything released without that sort of thing gets crapped on. It's kind of like mu;tiplayer in video games. Even if a game is 50 hours of the best storytelling ever, it will probably lose some points for not having team death match. sure, it seems stupid, but really, it seems to be what people demand. Just like they freaked out over whether the current gen could play DVDs, though DVD had become so ubiquitous at the point of launch that most microwaves come with DVD functionality (and are moving to Netflix).
I'm kind of hoping they have to break from their subscription model, though.