At the end of the movie, Jim Castillian says to Steve Austin that he wished he had a father just like him. This is an inside joke, as Jim Castillian was played by Lee Majors II, Lee Majors' real-life son.
Technically, there were two other bionic people besides Steve and Jaime. Barney Hiller, who was in "The Seven Million Dollar Man", was a race car driver who suffered an accident and had both legs and both arms replaced by cybernetic attachments, and Andy Sheffield ("The Bionic Boy") also had bionic implants.
The only bionic character from the series who did not make it for the return (aside from the "Bionic Boy") was Max the bionic dog. Dr. Rudy Wells does make a mention of him though when he is visited by Steve Austin in his O.S.I. laboratory. O.S.I. secretary Peggy Callahan, played by Jennifer Darling also didn't make a return appearance.
Steve's stated reason for his not assisting Chris Williams on his final mission, and thus not being there to possibly save Chris from death, was merely that Steve had retired from the O.S.I., and so he didn't want to participate in any more missions. Although it is not brought out in the story, however, an obvious implication is that another reason that Steve would not have wanted to accompany Chris Williams, is that he would have felt awkward working alongside someone who was Jaime's new heartthrob.