I've been sceptical of this "Nintendo fans only buy first party games" idea but thinking about it, rational people that want third party games would have long given up on Nintendo consoles leaving a fanbase that would consist mostly of Nintendo-only gamers.
I still don't buy that argument. I'd consider myself a casual gamer (if I spent more than 5 or so hours a week on gaming, it's unusual) yet I still bought 35 3rd party games for the Wii.
If Nintendo ever released a console that was on par with the competition in every way, I don't see how it couldn't be a success. As long as it was easy enough to port to, it'd get plenty of 3rd party games; just look at how many 360/PS3 games got ported to WiiU early in its life. And it'd have the advantage of having Nintendo games, Sony and Microsoft can't match 3D Mario games and Zelda games with their exclusive offerings unless they throw tons of money at developers. But Nintendo never has done that. Maybe I'm wrong but I just don't see how it would fail.
Anyway, with a WiiU under the Christmas tree, I hope things improve. While I wasn't a fan of the idea of the WiiU when it first released, the price drop and idea of off-TV play sold me; plus I'm not spending $400-$500 on a console that doesn't even have a game packed in so PS4/XBone were out of the question.
I'm going to be optimistic and say that December is going to be a good sales month for Nintendo. There's been so many good sales over the past couple weeks that are drawing people in (like the Skylanders bundle for $219, the original bundle and Zelda bundle being on clearance at some stores, gift cards galore with purchase), it's gotta at least help some.