Well, Jobs' children are still alive. I can't believe they too would be so mad at their grandfather that they wouldn't want to meet him. He should wait till things calm down and then knock on a door in Cupertino.
One point Jobs' father made was that he was surprised Steve didn't contact him to find out information about his family's medical history. I was adopted, too. I never had any inclination to track down my birth parents (not out of anger or anything, it's just something that's never interested me). Now that I have a flock of kids, however, my wife and adoptive mother are pushing me to track them down so I can learn about my bloodline's medical history.
Sure, ok, I guess if they want to hate/ignore him for eternity that's their right. But he seems like an old man with some remorse and a broken heart. Maybe he's actually a villain who really wronged their biological grandmother -- who knows. But total estrangement seems extreme.
Anyway, if I were him I'd make the trek to Cupertino.