and with the 3DS getting all the attention right now, the fact that Nintendo hasn't been actively promoting the Wii U AT ALL since E3 could see thems struggle a bit both during and after the holidays as many shoppers have already made up their minds about what they're going to be getting their kids and family for Xmas.

People who will buy a $250+ Wii U just for NSMB U but not a $170 3DS just for NSMB 2? 

I'd understand if the Wii-Sports like audience or Nintendo Core audience were transferring immediately but I don't think there's enough there yet. There's going to have to be 3D Mario, Zelda, or Smash Bros for the latter to switch.

Really depends on profit margin rather than units sold. Iwata will be pushed out if the first two Qs of Wii U are still in the red I think.

That's a good point... for a company that was always weary about releasing so many sequels to their games so close to each other (hence the reason why we routinely had to wait anywhere from 3-5 years for new Mario and Zelda games for the past 2 decades), Nintendo sure has been in a Mario frenzy lately.  SM3DLand and NSMB2 have been released less than a year from one another on the same console, and now we're getting another installment in the NSMB series mere months after "2" (which is actually the 3rd game so far counting the Wii version).  And I'm sure by next E3 we'll see another Galaxy or similar style 3D Mario game for the Wii U as well.

It's possible that parents could be suffering from Mario fatigue by the time the holidays roll around... and with the 3DS getting all the attention right now, the fact that Nintendo hasn't been actively promoting the Wii U AT ALL since E3 could see thems struggle a bit both during and after the holidays as many shoppers have already made up their minds about what they're going to be getting their kids and family for Xmas.