The Israeli Air Force, deeply embarrassed by their inability to perform as promised in the 2006 war in southern Lebanon, made a lot of changes before going after Hamas in Gaza in late 2008. Most people only noted the massive surprise attack, with dozens of targets taken out within three minutes by Israeli warplanes. That was an impressive example of precision bombing. But when the Israeli ground troops entered Gaza ten days later, other air force innovations were largely invisible to the public.
Since 2006, the air force has made radical changes in the way it coordinats its operations with the ground forces. To do this it mobilized dozens of older (some retired) fighter pilots and used them to staff air support coordination detachments at brigade headquarters. These officers were in turn supported by new technology that provided the air support coordination officers, and the army commanders they supported, with more real time video from UAVs and aircraft. The objective of all this was to increase the speed and accuracy of smart bombs and missiles hitting targets the army wanted taken out.
The air force tracked targets outside areas where Israeli ground troops were operating, and trained to find, and keep tabs on, key Hamas personnel and weapons (like rockets), and hit them when there weren't many (preferably any) civilians around. Each brigade also had its own attack helicopter squadron, which the brigade commander could use any way he saw fit. But he also had in his headquarters, an experienced attack helicopter pilot to advise on how best to use the gunships. Again, the idea was to use aircraft and helicopters more quickly and accurately.
Unlike 2006, the air force did not underestimate the enemy this time. That's largely because the air force has regularly been carrying out attacks in Gaza for the last two years, in response to Hamas attacks, usually with rockets, on Israel. The "Gaza War" operations were simply an expansion of that, doing more attacks in a shorter period of time, and in closer coordination with the army.