Legal Disclaimer: I am not endorsing Iatkos5i or any of these methods. This is more a collection of experiences that I have come across. In theory with this setup one would be able to develop iPhone applications using the iPhone SDK, and use the current Unity version while working on a PC to develop Wii and iPhone Applications. I make no promises or guarantees for any of this- I'm just passing along the resources and providing you with a Google session starting point.