In an interview with UK’s Guardian Unlimited, Will Wright has announced that a version of Spore is being developed for the Wii.

We’re doing Spore on the Wii, and we did MySims. It takes significant re-thinking to work out how you’re going to do it. PS3 and Xbox 360 are similar enough that you can basically use the same system for both. So it comes down to what the interesting major platforms are and which markets we want to hit.

I am very excited to hear this.  I have always thought Spore would be a perfect fit for the Wii.