Think of it this way, if somewhere along the line, CLE was able to trade DW for Bibby straight up, do you think they would (cap issues aside)? I think they would in a heart beat and that they would be a much better team for it. Look how much Atlanta improved in the end. I think you can credit Bibby. How well would they have done if they had DW? It took a while but Bibby was a very important player in getting the Hawks to "click". CLE still doesn't have a real PG and they are not really clicking. If they had Bibby (who is only 29?) I think they would be playing much better.
Disagree with you here. Atlanta and Cleveland are two very different teams. Atlanta needed someone who could facilitate their offense with their young, athletic stable of studs.
Cleveland's offense revolves around Lebron. They don't need a playmaking PG to facilitate. They need a PG who can help them get into their half court set (which West has done quite well), and then they just need to get the ball into Lebron's hands. Plus, Cleveland is a more defensive oriented team...and Bibby just doesn't fit into that role.
Bibby, whom you've stated is "only" 29. But you can tell just by his play, that he has lost a step. He's just not the player he was when he was in his prime in Sac (and he was fantastic when Sac was a good team), and gets dominated by younger, quicker guards.
Bibby fits Atlanta, and Delonte fits Cleveland. I don't think either team would be significantly better (or worse) if the two players suddenly swapped teams.