My short list:

1. More face models and jaw/eye/nose/mouth parts to play with.
2. Body scars and tattoos.
3. Selectable horns for Au Ra.
4. Scale colors for Au Ra.
5. A butt that isn't as flat as Steven Tyler's (doesn't have to be customizable, but an overall increase on the base body and gear would make a huge difference).
6. Fangs for Seekers.

I don't expect a massive revolution of the character creator, but I think everyone can agree it's severely lacking in places.