During today's Build 2015 keynote address, Microsoft confirmed that it has set up a way to allow apps made for Android in Java and C++ to be quickly complied for Windows 10.
Those apps will take advantage of existing Android code but developers will also be able to use the Windows platform tools to create new Universal apps. This should save developers both time and money by allowing the bulk of their code to be reused.
Apps can still use Windows APIs such as location, and they can run in a Windows Security container to allow for a trustworthy experience. Apps navigation will be integrated with Windows navigation model so they'll feel just like any other apps when you're using them. Even Live tiles and integration with Microsoft services can be used with these recompiled Android apps.
It's not about running Android apps on Windows. It's about making it easier for current developers on other platforms to bring their wares to Windows.
Stay tuned as we will have more news from the Build 2015 keynote throughout the day.