We heard back in December that Sony's fledgling Music Unlimited service would eventually be spreading its wings to cover even more operating systems, and here at CES 2012, we've learned that it's Apple's own iOS on the docket. Tim Schaaff, head of Sony Entertainment Network noted this week that the company will offer a gratis iPhone and iPad app for Music Unlimited "at some point this quarter." It's bruited that the iOS edition will offer offline caching for subscribers to its service (at least the premium ones), enabling 'em to save playlists f
