Going back to the new IP discussion...
I believe the reason why new IPs are important to any company is because it keeps a lot of people working, it keeps companies fresh and more new blood is inserted into game development (as in new employees, creators and such).
I believe that when Ian and Lindy say they want the next big new IP from Nintendo they mean they want a new franchise that could rival the excellence of Mario, Zelda, Kirby and Pokemon, a game that becomes a worldwide hit, not just a cult classic or something like that.
The reality of the situation is that Miyamoto won't be around forever. Either he will retire or die while working at Nintendo. Right now he's pretty much the glue that holds the company together. He provides most of the innovation at the company and he can't be everywhere. Nintendo should try and focus on young developers or creators with potentially good ideas so in the event that Miyamoto leaves forever they could have someone to keep pumping out new ideas.
And they can. Remember, Pokemon was just a small game about catching creatures in the wild and training them to do battle. It was a simple game with crude graphics, simple music and some limitations. Yet, the gameplay was solid enough that it brought a lot of new fans in and became a worldwide hit.
While Animal Crossing didn't create a similar sensation it also brought a lot of new fans in despite its simplicity.
Like I mentioned earlier at one point or another ALL major franchises were new ideas waiting to be tested. And they got where they are today because publishers were daring enough to give them a chance.
So to sum it up new IPs are important because it keeps a company fresh and relevant and gives birth to young creators who might be tomorrow's creative leaders.