I think Bell has the potential to be a good pick-and-roll finisher, which is generally an important trait for a big and prevents defenses from ignoring him. He also has the athleticism to switch across the spectrum--you may not want him guarding a backcourt player for long, but he looks like he could survive such a switch long enough to help snuff pick-and-rolls.
If, at the NBA level, he's an excellent rebounder, good switcher on pick-and-roll defense, good at rim defense and a good finisher as a roll man, he'll be solid value even as a mid-first round pick. If he adds another skill like shooting or reliable passing, he could even be a steal. I'd be okay with the team taking him at any of their picks, really.