Air power is being redefined now. Precision bombing has already changed the face of air warfare. Now we see the proliferation of unmanned aerial vehicles (drones). "Swarming" UAV's will make conventional air defenses obsolete. But, then, as CHAMP technology (we have already fielded it) proliferates, not many things that depend on printed circuits (including computers) to fly will be able to get off the ground.
Then there is the never-ending "mine shoots further than yours" evolution. Sensor fused weapons allow air attacks from further and further distances as air defense system struggle to match the ever increasing engagement ranges... and vice versa.
It all changes from day to day.