Honestly if the Wii U sells under 7 million for the entire year in 2013, Mr. Iwata should step down and be replaced with someone more market savvy.
I know that may sound harsh, but seriously that would be a disastrous follow up to Nintendo's most successful console, and coming on the heels of the 3DS problems launch-wise ... it's time for a change.
To me if the Wii U does that badly, Nintendo's leadership ultimately has to take the blame. Honestly even at 8 million ... I would say Iwata is on a short leash.