Do you know what kind of coat this little guy will have?

A family members dog recently had puppies and I am going to take this little guy when it is time. He is only 3 weeks now but does anyone know what kind of coat this guy could have? He is a Jack Russell and Japanese Spitz mix. He is lovely and fuzzy at the moment. I don't mind if he is long or short hair, I am just curious.

Thanks in advance for any help and insight.