The race for air superiority has officially begun.
For a few years, there were a few flyers here and there. Marty's ork fighta-bomba which made a lot of noise but didn't really bother my marines. Stu's Tau dropship. Not a whole lot worth worrying about.
But then I got the Helltalon and things seemed to heat up. Here was a fyler with definitely edge. Deadly and fast and used to devestating effect against a series of opponents, talk began about how to best model Anti-aircraft mounts on vehicles. Some Eldar players got some Vampires and Pheonixes and it now seems that having the AA gun for the army is not such a bad idea. Dalton is building his own flyer based on a Warthog model. White Dwarf mag #301 had rules for flyers intercepting each other in a battle report. Corey is talking about building a firestorm grav tank for AA support. I'm considering building my own AA support vehicle or platform.
The wildest part is that I don't see this phenomenom going away. Flyers are here to stay and smart players will start taking this new type of threat into account.