For me:
1 - A curly long hairstyle with bangs for Blood Elf Females;
2 - Elf ears for the Undead;
3 - Red skins for Draenei;
4 - Druid of the Flame skins for Night Elves;
5 - Grimtotem Tattoos for Tauren;
6 - Light gray skin for Trolls.
What about you? 
Here you go my friend!
Ya beat me to it 
Flaxen blond hair for my dwarf priest!
(No not the tint-blond white with the pink stripe down the middle we are getting, the actual flaxen colour I had seven years ago!)
For a Warlock I can’t believe you missed the most important thing… Demon appearances on Barbershop just like Druid animal forms. Pick out your Imp, Succubus, Voidwalker, Fel Puppy, Felguard! Gain new appearances by defeating existing enemies and stealing their bodily form. Kill 5 Pitlord bosses and now your Felguard can take the appearance of a smaller, Pitlord!
I’m waiting for more Draenei stuff.
Scars. Broken horn options. Let me toggle the tendrils individually (in my head this warrior lost the left two but has the right two).
Scars.
That would be nice, but I don’t think they will do it because Warlock pets are not part of the Warlock, unlike Druid Forms.
You’re just giving them a physical form to inhabit, their essence is formless and they can change the more power they gain themselves, their current form is not permanent.
I’m just saying that since the Warlock Demons aren’t part of my character, they probably won’t be included in the character customization revamp.
They will just stay as glyphs even though the whole Warlock Demon system should be revamped so that we can gather ingredients for a ritual to summon a Demon by calling their name in a magic circle and beat them in one on one combat to gain them as a pet like it was in Vanilla but better and cooler with options and stuff.
My wishlist is as follows:
Nightborne
Improved hair textures, new face options, new skin color options. Nightborne just aren’t on par with the other Allied Races.
It’s been 2.5 years since their release and with almost unanimous criticism on the internet, they’re still untouched.
Please fix. Thnx. 
This.
Also a legit Void skintone for Void Elves. I want that Alleria Void Form tone or something that isn’t blueberry.
Also, I think most BEs would look fab with the new Draenei hair styles so I am willing to share them with my ladies running around red side 
((overall I’m pretty friggin’ happy atm with Draenei and Tauren))
I’d love if Orcs, Nightelves, and Draenei could have this hairstyle:
https:// wow.zamimg. com/uploads/screenshots/normal/928340.jpg
I could go on for hours on what I want, but I mainly want a forest troll green skin for trolls. A lot of people were mislead into thinking that’s coming by Wowhead because Wowhead used it to show off female war paints, not because the skin itself was datamined.
Taunka and Yaungol Tauren customization.
Forsaken Blood elf skin color and eyes.
Upright posture for pretty much all races that don’t have it. Even for the race that in the faction that is normally upright, the Worgen Male.
Breast sliders.
Shoe coverings for trolls. To this day I laugh at troll players because of this 
1 - Shoes for Trolls.
2 - Nightborne improvement they really really need it.
2 - Upright stance for all hunch races but mainly forsaken.
Let’s see here . . . unfolds paper
Regular hair colors for void elves (human or blood elven, so long as blonde and orange are involved)
Ear options for allied race elves and orcs Akin to their core counterparts
Lightforged getting tail options
Hair styles for allied races, specifically normal hair for void elves(not blood elf styles) we can counter These with new voidy styles as well (one void style for every normal)
And lastly . . . I want my light blasted eyebrows to match my hair color! Geeze ya had it in the new female gnome model preview what happened? Also female dwarf eyebrow matching as well . . . don’t see why goblins are the only ones released from The brown eyebrow Abyss.
A mullet for every race.
And gender.
Let’s get Joe Dirty up in here.