Puppies' ears stand at different times and they can be helped by taping or using Breathe Right strips. Sometimes just shaving the hair off them will get them to stand. That was the case with my Sadie.
A sparse coat on a Yorkie pup can be a good sign, actually maybe better than if the coat is very thick. There is a great sticky on here that you should read -- it helped me a great deal. Here is the link:
http://www.yorkietalk.com/forums/showthread.php?t=16045