At Nintendo's Q&A session earlier today, Zelda creator Shigeru Miyamoto revealed that prior to development of the upcoming Skyward Sword, he'd given the franchise team a warning: either it was the best Zelda ever made or there would be no more Zeldas.
He also said the same thing to the Star Fox developers. Either Star Fox 3DS is the best one ever, or no more Star Fox games. Both franchises would go back in the box.
Rather extreme threats (and, to be fair, he surely couldn't have been serious), but sometimes if you want the best out of your troops then you need more stick than you do carrot!