It's a dedicated video (PAL or NTSC) Arduino shield with passthrough capabilities. Nothing fancy, just a sync separator and some passive electronics. Obviously, it needs to be mated with an Arduino (additional one, alongside APM, of course), but it's plug and play and comes with a neatly put together library. Question is, can this + Arduino physically fit an average ArduCopter?
If so, it might be the ticket to beginner's quad computer vision experimentation (plus, you get an OSD generator extra ;) on the cheap ($50ish + camera).