Thanks everyone. We're working on "watch me" in the house and so far, he's doing well. There's still lots of muddy, icy, snowy muck in the back yard, so working outside will have to wait for a while longer. I've found some treats he's over the moon for, so will start using them on walks.
He's not a wild man about chasing other dogs/squirrels, etc. There's no barking or growling - just that intense focus and stalking like behavior, then the jump or pull to run. By that point, I'm ready for it. Today, he wanted to go after a barking dog across the street from us and I just kept moving along, talking to him, until he became interested in what was in fornt of him. I suspect it will take some time, but he's at least manageable.