I personally don't see Iwata and Nintendo doing a lot wrong. The 3DS is defying so called experts by selling well despite smartphones and tablets. Wii U is a good product with good games coming.
They have made a few key errors with Wii U, mostly the bundled software (should have been Sports Club, not Nintendoland - which was a waste of resources), launch titles (NSMBU should have been more unique, a core title should have been present...delaying and upgrading The Last Story would have been a great move) and marketing (let's be honest, it's terrible so far). But overall I like their product strategy and with a little success for Wii U they are in great position to make money. For all the criticisms, they still have nearly a 3rd of home consoles sold and about 85% of handhelds. And they make far more money than competitors because of the high profits on 1st party software and hardware that doesn't bleed money.
