This is one where I really really wish Reggie had been called on the carpet earlier and forced to play the guy.
From what I have seen, I do not think Sheldon has it. He combines stubbiness with a complete lack of explosiveness, and its just very hard to picture him becoming a starting guy on a good team. And he's a stubby 4 -- really not much taller than KT, although much much broader -- which limits his usefulness off the bench because of lack of versatility.
All is not totally lost, he does have bull strength and can bounce around the skinny ninnies of the league. If he had a mean streak, which I have seen no real evidence of, he could have a role as enforcer. In any case its funny how he burrows around in groundbound fashion, just bulldozing his way from one end of the paint to the other and grabbing rebounds and hitting layups just by powering his way into prime position. But while its what he can do, how he can be effective, it just doesn't look like anything you can really build around.
But would have loved to have had a full couple of months to be sure before making decisions about ouor PF position this summer.