In a perfect world the game would be updated with the X-2 battle system, I would prefer turn based for the remake, but I don't see it happening. I also don't want anything from the compilation in the game, especially not emo cloud. The game must also have Mukki and the stairs.
It won't be Emo AC Cloud. We'll get classic Zack-ish Cloud.
They won't be turning down the Compilation, though. Be it through DLC, in-game bosses, little bits of added in-game lore, they will not miss a chance to grab literally EVERYONE and get them on board.
Now, for the biggest question. Who's doing the soundtrack? Will we see the return of Uematsu? Or will Ishimoto (Crisis Core, Type-0 HD) or Hamauzu (Dirge of Cerberus, XIII series) take over? Or will we see a new contender take over?
My vote's on Ishimoto. Crisis Core had the best OST of the Compilation not done by Uematsu, and I'm not sure he's going to work on this.