The word gets used as if it's well defined, but I have never heard a non-metaphorical description. "A war fought in cyberspace"? That means nothing. "A shootout on the info superhighway"? That means even less.
And yes, I've read about Titan Rain, Ghost Net, Operation Aurora, Coolswallow, Giving Wings to the Tiger, The Dark Visitor, Estonia's "Web War One" and more. All of this talk of "cyberwar" strikes me as merely a modern-day regurgitation of Cold War Boogie Man Stories, like Missile Gaps, and Bomber Gaps, Bears in the Forest, and Yellow Hordes, and stoic Spetznaz supermen. The emergent behavior seems to be lining up a successor magic funding word to "terrorism", should bin Laden die.
Point in case:
"Cyberwar refers to conducting military operations according to information-related principles. It means disrupting or destroying information and communications systems. It means trying to know everything about an adversary while keeping the adversary from knowing much about oneself. It means turning the "balance of information and knowledge" in one's favor, especially if the balance of forces is not. It means using knowledge so that less capital and labor may have to be expended."