Microsoft announced that they've released a tool that will help developers migrate their apps from iOS for WIndows Phone 7. They said that there's no magic wand that will do the work for you, but they have worked on a map that will make the process less arduous.
Mapping iOS apps for WP7 is a little less stressful
The API mapping tool is available at http://windowsphone.interoperabilitybridges.com/ right next to a 90 page paper that's titled, “Windows Phone 7 Guide for iPhone Applications Developers”. The site also features help for developers in he form of developer stories and a compilation of other resources for developers. Microsoft says the tool is something like a dictionary.
Specifically, developers look at the iOS API calls and look up he equivalent classes, methods and notification events for WP7. “Developers can search a given iOS API call and find the equivalent WP7 along with C# sample codes and API documentations for both platforms”, says Microsoft's JC Cimetiere.
These codes let developers migrate “short blobs” of their iOS code. To begin with there are three APIs that can be mapped: Network/Internet, User Interface and Data Management. Not all APIs can be mapped yet but Microsoft says they're working on this. They're also working on similar tools for Android.