There are definitely differences in facial structure and it does depend on the parents. Coats, like size are not always accurate with predictions, but with a reputable exhibitor breeder your chances of getting the adult yorkie you're looking for are much better than buying from a less educated breeder (most byb's), pet store or puppymill.
This is a recent thread with puppy - to- adult pictures.
http://www.yorkietalk.com/forums/my-...cs-please.html