Look I'm going to save you the pain and tell you what this topic is going to largely consist of.
WE HAVE ENOUGH ELVES IN WoW.
The horde could have something to balance it out sure but I think the Alliance players would see this as a cop out so I don't ever see it happening unless Blizzard moves the High/Blood elf choice to to Pandaran state of affairs and puts... I don't know Ogres. Where the Horde's missing slot is.
Again, to Alliance players this would be a cop out. It's not going to happen as nice as it would be.