Please understand.
Not much they can really do by chaning management at this point. Whatever games are going to sell the Wii U need to be in development by now, and whatever deals need to be made need to have been made. The only real room they have to change is with regards to their ad campaign.
Basically, the Wii U is going to survive or fail based on Iwata's plans. If a new guy comes in now, what is he supposed to do? Beef up the hardware through magic for third party support? Singlehandedly get the next killer app out by next Christmas? They're going to be stuck with the situation Iwata created.
So, there basically should be a ticking clock policy in effect. Iwata should have until this time next year. Sales pick up and profits are high, he stays. If that's not the case, then he needs to leave, and the next guy has to come in with his focus purely on the generation after.
