Silly question if 8.4 gets its full release (asuming it has to for Apple Music) and we havn't had the GM yet do we just download 8.4 as normal
8.4 full release tomorrow?
You can just update OTA as normal. From (https://developer.apple.com/support/pre-release-software/):
"... devices and systems running pre-release software can be upgraded to future pre-release versions and final software releases."
There may, nonetheless, be merits to backing up and doing a fresh install via iTunes.
Yes, I can't wait until 8.4. I can't wait to see how iTunes radio will sound like. I am thinking of joining the free trial for Apple music. How exciting?