Windows 10 is still months away from being released. Also considering this will be a special build of Windows running on ARM processors that the standard windows MAME versions will not work on it as the developers will need to compile a specific build for ARM chips. They have the code, since it runs on ARM in linux, they just need to compile a version for it. I doubt this will improve compatibility as it will most likely be the same exact code, minus windows specifics, running on ARM chips now.