I really welcome this move from Microsoft and hope it will attract even more customers to iTunes and Apple Music. I truly believe it could, because I genuinely think Apple Music is a great music streaming service. Tried Spotify for a while, and I've been looking at some others as well. But apart from a somewhat confusing design it offers the best experience in my opinion.
The question however remains: what kind of iTunes will it be? The same that's currently available as a regular program? Or something that's actually much better? Before I've had my first Mac I always used iTunes on Windows. And it wasn't particularly that good. Hope they've fixed that in this 'Windows Store' version. Might give it a try on my Windows 10 BootCamp.