Ok, first thing that shot at me was his tail, which you've already addressed. There are some techniques to lower a dog's tail that serious contenders use. Second, it looks like his ears are a taaad bit more large than they should be. Also, the length of muzzle looks nice, but it's a bit too square. I bet it's the angle of the photo, but his topline probably looks greyt in person. It's looking a *little* off, but it's because the angle of the photo.

Another very big thing is that his hindquarters are looking very straight. According to the AKC standard, he should have well-bent stifles as is pictured in the drawing, but your pup has pretty straight stifles. That can easily be remedied by some crafty handling, but I'd keep that in mind (next time you stack him, try to make his hock perpendicular to the ground). Don't take my word for it, though

Can he be shown? Yes, if he's registered and unaltered. But would he make a good show dog? Well, that's tough. Fix his tail carriage and hindquarters and try to choose a head position that doesn't make his muzzle look too square. He doesn't look too bad, but I would invest in a puppy specifically bred for show.

Is this a pet or a show prospect? I hope this helps!