Ok, before we get into it I would just like to say that I am NOT trying to incite a flame war here. I would like people to, just for a moment, turn away from the Shigeru Miyamoto shrines and ponder this question.
Is Shigeru Miyamoto past his prime?
I guess the better question is, should Nintendo stop relying on Miyamoto as their bread and butter developer/producer? Because it's quite apparent that Miyamoto can still churn out a great game, but my concern is that Nintendo is relying way too much on him, to the point where it may be stifling his creativity. Ever since the Fall of Nintendo with the N64 it seems that they have really been pushing Miyamoto because he was one of the few things that worked. He was already god-like with his NES and SNES games, but it wasn't until the N64 and the departure of major 3rd parties that his games became the REASON to own a Nintendo console. His games, and the various spin-offs they spawned have been, largely, what kept Nintendo afloat. So it's understandable that Nintendo regards him as their precious commodity and the ace up their sleeve.
But is this ultimately a bad thing? I mean, I love Miyamoto as much as the next guy, but even I have to admit that, starting from midway through the N64's life his games, while great, have become stale. They all lack the innovative edge that made his earlier works legendary. Even Twilight Princess, easily his most anticipated game that's been reeleased, has been touted by diehard fans to be great, but still just more of the same Zelda gameplay with no real innovation. His big name franchises have been so overused that almost ALL of them lack the sway they once head, no matter how great they are.
I personally believe it's because his creative energies are spread over way too many projects. Nintendo, as well as his fans, are starting to expect way too much of him, more than he's probably currently capable of. Nintendo fans have become gamers who mostly thrive on Miyamoto games, hungrily waiting for the next installment to one of his big franchises. I think that, in his rush to make sure people have the next big Mario/Zelda/Metroid game, he hasn't had time to do what he does best: Innovate and create new and inspiring IPs in his sleep. Sure, there was the short-lived Pikmin series, but you could tell by the marketing that Nintendo wasn't really putting their stock into those games like they would have in their SNES days, and Pikmin 2 was terribly rushed. There was the phenomenon known as Nintendogs, but of his upcoming major releases the only one that seems to be set to really innovate in it's genre is Super Mario Galaxy--which, again, is another Mario game.
Miyamoto is easily the greatest developer of all time, but let's face the facts: the man's getting older. Should he really be carrying the brunt of the work? I don't think so. In my opinion, Nintendo should really start to focus on new talent. Fresh new faces with different outlooks on gaming and different styles and philosophies to contribute to Nintendo. Take some of the weight off of Miyamoto, and let his creativity flourish like it used to when Nintendo didn't need his games to survive. Sure, it might mean less Miyamoto games, but I think the payoff would be more innovative, hype-grabbing, industry shaking masterpieces of the sort that defined his earlier career.