One of the movies I'm looking forward to is Stealth, due out on July 29, which is about an unmanned artifically intelligent plane that goes haywire and starts to fight manned aircraft in its own squadron. The trailer looks great!
Interestingly, this month's Popular Science features an article about the next generation of unmanned military planes. There are plenty of people who believe they're the future of air combat, since they are smaller, lighter, faster, cheaper and more manoeuverable than their manned bretheren. In addition, if they get destroyed, no human pilot is killed.
The tricky part is being sure that its systems are good enough to not accidentally destroy the wrong target and/or unnecessarily kill civilians. Since cruise missles already have some of this capability, it doesn't seem like it will be that long before unmanned air combat becomes a reality.