The U.S. Air Force is flying more over Afghanistan, and doing less. That's because they no longer have a monopoly on GPS guided weapons. In 2007, coalition (mostly U.S. Air Force) warplanes flew 13,965 ground support missions, and dropped bombs or missiles 3,572 times. Last year, there were 19,603 missions, and guided munitions were dropped 3,369 times. More missions, but fewer munitions used. The main reason is the growing availability of GPS guided artillery shells (Excalibur) and rockets (MLRS) that are fired from army vehicles. There are also more helicopter gunships, which the ground troops prefer to fast moving jets.
In 2007, about 4,000 Taliban were killed, and last year that rose to 5,000. Early on, the Taliban tried to figure out a way to neutralize the smart bombs. At first, they thought they could calculate how long it took for the bombers to arrive, and attempt to flee before that time. But the time was variable, and often not much at all (if the jets happened to be overhead, or within 50 kilometers at the time the Taliban attacked, or were spotted). But with the artillery (Excalibur and MLRS), GPS guided fire can be on the way in minutes. It's tough being a Taliban commander, when you're most important decision is to calculate how soon you should order your guys to run away from the enemy.