The posty hocks and the really short neck are the first things that pop out at me. He might grow into his neck, I don't know, but his hocks likely won't change much. I wouldn't worry about his pasterns very much just quite yet. When Rafe was that age, his were very upright as well but as he grew, they angled down and now are very nicely angled. He's a cutie but I would have to wait until he was older to give a definitive yes or no.
Glad to see you back Tiff. We've missed you