Microsoft has already announced their plans for "Project Astoria", which is designed to allow Android apps to be quickly ported over to work with Windows 10 Mobile. A recent job listing at Microsoft shows that the company wants "Project Astoria" to accomplish this task while keeping the original Android app binaries "unchanged".
The job listing says:
"Our Astoria team is delivering a set of new experiences for consumers and developers with the potential to make a huge difference for the Windows platform. The Astoria bridge enables Android developers to publish their unchanged binary to run as they are on the Windows mobile platform. This is a first for our Windows platform received enthusiastically by the Android community."
If that can indeed be accomplished, it could allow for a ton of Android apps to come over to Windows 10 Mobile. Microsoft is currently allowing developers to sign up for a Project Astoria beta testing program but the final version won't be available for all developers to use until this fall.