Even the current build of Remastered that you see streamed on Twitch right now (the closed beta) is using the original music and sounds upgraded to double the original sample rate.
Late to this, but I have to comment on how good this game looks now. Wow, they really did SC justice. Was lukewarm on the remaster as a whole, but for $15 I'm in.
I know we have some awesome GIFs but here's a video comparison between the old and new for all three playable races and extras. Terran Zurg Protoss etc.
Some of the new ones look fantastic in my opinion. Some got a big overhaul to closer match their SC2 appearances.
EDIT: Ah the heck with it all of them look fantastic to me!