Yes! Oh I've been wanting iTunes to split into smaller apps for a while now. It could easily turn into...
-Music
-Videos
-Podcasts
-iSync (for people who don't sync via iCloud; I personally wouldn't need this except for the occasional local backup)
-iTunes U as an optional App Store download
-Put Audiobooks in the iBooks app where they already live on iOS
-And an overhaul of the Mac App Store to display all apps, both Mac and iOS.
It'd be so much cleaner and would offer feature parity with iOS. Not even joking, a member of my own family, who's shall we say not super tech savvy, was stunned a few months back when I showed her that the movie she'd bought on her iPad was "in the music app on her Mac." Since the iTunes icon matches the Music icon on her iPad, and since she's only ever used iTunes for music, she genuinely had no idea that she would find a video file there, and had come to me asking where her Videos app was. Granted, I know that's not the norm - she's sort of a computer novice and most people don't have that issue, but still...it really should be consistent, especially now that iOS and OS X are becoming even closer in terms of performance and usability.
Anyway, yes, I really hope to see that happen soon. As for Windows, there's no reason why they can't continue to develop iTunes for that, or at least even a legacy version. I mean, they offer Apple Music for Android, so why not?