Subtle scars and the like apparently occur the more dark side points you have. I can't 100% confirm this, however.
Additionally, I could foresee a hairstyle alteration system after creation being implemented down the road but I wouldn't hold my breath either.
In otherwords, be patient, take your time on your character and make sure he/she is ready to step food in TOR!
This is true. The more dark side points you get, your face will change slightly, eyes will start to change color ... you can also disable this in options.