I think you might be a little optimistic or I might be a bit too pessimistic. We'll see soon enough. I don't think it's going to be smooth sailing for Nintendo and I hope they've used all this time to make sure NiN and the launch lineup is the best it can be.
Nintendo's strength is it's IPs and Nintendo develops its hardware to play to the strength of it. That's why Nintendo software is almost always quite polished and it's sales reflect this.
Sony and Microsoft, with their over reliance on third parties, are much more vulnerable compared to Nintendo.
If next generation is anything like the current generation, with multiplatform games being the norm, and I think it will be unless there is a console with ~70% of the market. Wii U will likely end up winning next gen, unless xbox or Playstation really show a game changer, they have nothing to stand on, to really pull in their gaming crowd, and I don't think services like live are really enough.
I could imagine Halo 4 becoming relevant, but the truth is, currently COD has killed Halo's popularity, and there is 100s of shooters released yearly (or at least it seems that way) so while Halo 4 could become the next big thing, it only has as much of a chance as the next shooter, with maybe the bonus of old fans who will buy the game, but will they make it relevant like it was early this generation? likely not.
Your last statement is why I am confident Wii U will win next gen, because if all of these third parties start releasing their games on Wii U, than there is really no competition between first parties, and with Nintendo releasing first, they will have the head start that they normally have to fight against.
Color me on the pessimistic side of the scale (surprise..)
Nintendo is not only fighting engrained sentiments that have settled over the past two decades.. it's also facing a gaming media that reinforces these sentiments.
It'll take more than a strong E3 with a strong inaugural year to overcome this, I think.
And you've nailed my sentiments on IPs and third-party reliance along with how they relate to Sony and MS. And yes.. Sony makes nice first-party games. But I don't see their first-party characters floating the gaming division like Nintendo's do.
Nintendo has been fighting this kiddy image since Sega's "Sega does want Nintendon't", I did a pretty through post on it 30 pages back or so, I'll look it up if people want me to.
on E3: No, I think a strong E3 will do EXACTLY that, it took one year for Microsoft to go from xbox barely being relevant to 360 dominating the market, this happened because Developers targeted the box, I expect this same thing to happen to Wii U, because it already is the talk of GDC, and will likely be the talk of E3.
This last paragraph is just supportive, Sony and Microsoft's in house games have no chance against Nintendo, and all Nintendo needs to do to change it's imagine is to have GTA5 announced for it's console (as a multiplatform) and it's own hard core adventure game along the lines of something like uncharted.
So you both just seem pessimistic to me, but that's ok, I am just hoping I'm right and you're both wrong, in the end I don't come from the future, but I can see it clearly enough. (I hope)