The music in this update will be the same music in the same places as was on PC version 1.3.0.7. I believe there have been some music changes and additions on the PC version since then; those will not be in this version but should come later as the mobile version catches up, content-wise.
There will be no cloud 'syncing' within the game any longer. The 'sign into Google' button on the main screen will no longer be there (as shown in various screenshots and videos before). There won't be separate 'local' and 'cloud' slots for worlds and players any longer; everything accessible will be on your device, and you can have as many worlds and players as your device has local storage space for.
The players, worlds and settings data will be accessible for manual copying to an internal SD card, a connected PC, or a cloud service of your choosing for backup, and of course you'll be able to copy them back to your device for restore. We'll have detailed instructions and examples for how to do this ready at the release time.