I'd rather see him come home to BOS somehow, but Spurs are a Class destination for him.
I'd be happy for him if this happens.
He'd keep the Spurs window open a bit longer...perhaps keep Duncan around another yr, too.
In any event, he'd be the primary Big for their future...not a bad situation for him or the Spurs. He is one of the most polished lowpost threats out there RIGHT NOW, and will get better defensively with Popovich.
A Big Al/Duncan frontline is giving OKC much more trouble than they did last yr's playoffs. If this happens, OKC's path gets a bit harder.