Blood Elf racial - Looking Good - summon a standing mirror in which the character preens and primps for 5 secs.
Disciple of the Light (Draenei) - Summons a Naaru companion which follows the player around.
Perhaps the Naaru could bathe critters in light and have them transcend (instead of other companions that kill critters.)
Tauren could have a 'peace pipe' racial wherein they create a small ring of smoke that acts as a sanctuary, one hour duration. Threat range is reduced for all players within the ring of smoke. Any player within that ring is treated as non-hostile to all other players and cannot be attacked. Any player who logs off within the ring of smoke or simply stands around in it gains rested XP as though they were in an inn. Cannot be used in combat, the tauren using it cannot use it while flagged, and cannot be used while in an instance. 1 hour CD.
I've always imagined that trolls were ideal for swinging tree-to-tree like the hozen do, and it would be a fun alternative way to travel at lower levels.
Perhaps give orcs a racial called 'unstoppable' where they choose a location and charge to it, knocking back everything they hit slightly. Give it an uninterruptible 2-second cast-time so players have some warning, and make it do no damage. Five Minute CD.
Gnome - Never touch the do. Anybody attempting to pet you is instantly transported into the nether, never to return.
gnomes should have an ability that allows them to crouch down and another player can punt them 10 yards or something
Gnome: I'm not a football. Punts other races 10 yards in the facing direction.
I have a weird idea for making Shadowmeld for cosmetic and less of a PvP bother, for those of us who prefer our racials flavor-only.
Instead of being on-use, your Night Elf would simply become slightly transparent at night time or in set "dark" zones, like caves, maybe Deepholm, etc. I would dial back to transparency a little so it's not taken as a semi-permanent stealth advantage, and then add an option to go without it as I could see some people not liking it (probably the same people who hate Shadowform but play SPriests!).
I'll admit I never played the RTSes, but isn't that how Shadowmeld is supposed to work in lore?
Plainsrunning is an popular choice for Tauren, especically since Worgen got Running Wild.
If Dwarves were to get something fun like the old Avatar state (get big and stoney), I think a similar one for Trolls would work where they go into a Dire Troll state (mostly just get big). Dire Trolls seem to be a induced state half the time, through magic or warping, so maybe they could do it for fun, too. Female model pending, of course. :P
Night elves should full on get their old WC3 ability back: at night, if they're holding still (and out of combat) they should automatically shadowmeld. Obviously, gotta be out of combat and not in a dungeon/raid/battleground.
Blood elves should be able to cast a mana-drain channel on anything nearby. Put a cosmetic debuff on their target that blue/purple tinges them for 5 minutes.
Worgen's transformation could be toggled between default (how it works now) or "day phasing"; ie, During the day they're human (except for when they go into combat, then shift back to human 10 seconds out of combat). At night, they're in Worgen form.
For Draenei, remember that Archaeology thing for Draenei that lets you teleport somewhere random? Give that to them as a passive ability, 30m cooldown. When you appear in the zone, animate it as a large pod crashing into the ground, and you character hopping out of the wreckage. :D
Tauren could conjure up an overgrown flora patch using the same graphical resource elements of whatever zone they're in (IE, they could conjure up a palm tree and some ferns in the Barrens, a small purple-barked tree in Ashenvale, ect).
Troll- Regeneration. Out of combat, can enter a meditative trance that restores 2% of your HP/Mana per second. (Basically, never need to carry food/drink.)
Tauren- China Shop: +1% multistrike chance
Worgen- Allergic reaction. Stealthed characters are one level less stealthy around you.
Looking these over, there are two lessons to be learned. First, night elves love Shadowmeld. Second, gnomes are sick of your crap.