I think Windows Phone is brilliant. Well-made devices and a great operating system, but the lack of apps makes it very unattractive to the general masses. Support for Android apps without needing to be redeveloped is a no-brainer in my opinion. No developer will see the value in converting an Android app over to Windows. It has to support Android apps out-of-the-box without the developer needing to do anything or no tool, no matter how great or smart it is will make developers change their tune, even if it is easy to do so.
At present there is no motivation for developers to develop for Windows Phone and no incentive for customers who adopt the platform. This is very much a chicken and egg problem, one I don't think they will ever solve for as long as they don't support Android apps.