While I don't foresee (or want) Blizzard allowing us to just swap racials around, I would not object to a "veneer" for racials. If they ever add some sort of option to change our displayed racial tag (so the race says High Elf instead of Void Elf), then the "veneer" could change the names, icons and visual effects of the racials while maintaining their functions. For example, if I select the "High Elf" option my race would display as High Elf and the "veneer" on my racials would make them change thus:
Entropic Embrace becomes Arcane Legacy: The visual effect, icon and name change but otherwise it mechanically works exactly the same.
Spatial Rift becomes Arcane Jaunt: The visual effect, icon and name change but otherwise it mechanically works exactly the same.
Preternatural Calm becomes Focused Mind: The icon and name change but otherwise it mechanically works exactly the same.
Ethereal Connection becomes Friend of a Friend: The icon and name change but otherwise it mechanically works exactly the same.
Chill of Night becomes Against the Darkness: The icon and name change but otherwise it mechanically works exactly the same.
Basically the "veneer" and racial tag display change would allow subraces within a given race. The same concept could be applied to other races, such as Wildhammer Dwarves, Sand Trolls, Grimtotem Tauren, Dragonmaw Orcs, etc.