Yea, but that's not what most mean by "write once run anywhere." I don't consider having to write separate view controllers for iPhone and iPad "write once run

Yea, but that's not what most mean by "write once run anywhere." I don't consider having to write separate view controllers for iPhone and iPad "write once run anywhere." In fact that's not much different than many existing cross platform applications that have a platform agnostic core with a layer of platform specific UI code on top.