You're missing the point I'm trying to make. There are already languages which will run on both platforms, why isn't everyone using them for everything already. Well, because there are problems....
You will be able to write some of your business logic and have that transferable between both platforms. But very soon you will need Frameworks. Google will have to implement UIViewControllers, UIButtons, CLLocationManagers, etc, etc.. And they will also need to behave the same way, implement the same features, properties, bugs even!
As a full time developer it's not particularly difficult to write in a different language. What's difficult is to remember what's available in the frameworks on the platform you are writing for. What quirks you will have to work around.
This is not going to help get iOS apps onto Android phones, not until there's a shared framework which will run on both devices.