Cosmetic Spell Alterations.
No concern over whether they're balanced since they all do the same thing.
But they all actually look like the spells would be cast by your race.
No more troll/nelf priests / priestesses looking like they worship the holy light.
Warriors would have an image over their head that actually belongs to a member of their race when they switch stances.
Night Elf druids wouldn't have to have sun imagery in their druidism, the tauren could keep that.
We could see differences in the way the various Paladin Orders use The Light / An'she (because it's dumb that Blizz treats An'she like just another path to the Light, or the Tauren name for the light. *rolls eyes*).
Could even be expanded to racial warlock pets.
And best of all, if you wanted to change spells, say your orc takes up troll religion/magic, or your gnome decides that rather than titan vitae it WOULD like to use the Light?
Just go to the racial capital, talk to an NPC, and get your spell graphics switched, there could even be 'stolen spellbooks' to use the aesthetics of members from the opposite faction in case you're really attached to your Tauren using the Light (traitor! *scowls*), or your Dwarf hunter wants to use Goblin-designed traps and such.