We have kept with the go-out plan that I mentioned before. The focus and comprehension of this exercise is improving with each day. Sunday morning we went out for 20 minutes. Every single go-out he did was perfect and at 30ft. I only had to 'mark' him to a spot once, and he went straight out and sat when I told him. That wonderful glimmer of hope made my day.
This evening we went to the busy play ground again and did some more go-outs in the field behind it. Not quite the repeat performance from Sunday since he stopped short twice, but pretty close. I was most impressed with the fact that he didn't even bat an eye when I sent him on a path that included surface changes (grass to blacktop/sidewalk, grass to blacktop to grass again, etc). Of course the kids didn't bother him at all - that is one thing that isn't a very good distraction any more.
I am very pleased with him. We just have 10 more feet to add on, and then we are back to marrying the go-outs with the directed jumping again.