I'm sure it's a content delay. It takes a long time to build textures, monsters, maps, and the like with graphic engines like this.
I think if it were a content delay, they would have known long before this.
Of course, it's possible that they did, and just didn't tell anyone.
What made Half-Life? A good game. What made it a classic? Counter-Strike.
I disagree. I think that Half-Life was a classic in its own right. BUT...it was a classic for reasons of content design, not technology. It was built on someone else's engine, and nothing about the tech was particularly inovative, or even close to the cutting edge.
Half-Life was great because of its immersive story, and well-designed evironments and characters.
Valve has only 1 complete game under their belt. They're not genius.
It does indeed sound like they are starting to believe their own hype. And we all know what happens when game designeers go too far down that road. Do I need to say the name?
Yes, they kept quiet about it for a long time, unlike the name I won't mention, which was smart. But they should have kept quiet until they knew they could hit their release date. It was a smart marketing strategy and they should have stuck with it.
Look at what's happened to public opinion.
A month ago, everyone's reaction was "Holy ...*&*(^. Must...get...game...".
Now the doubts are starting to creep in. First the whole Steam fiasco, now the delays (most likely on account of same)...
I think they are trying to do too much, too fast; a common indication of hubris.
My advice to them, were I in a position to give such, would be as follows:
"Concentrate on getting HL2 out the door. Delay Steam, and just release HL2 with WON IDs. Then you can focus all your effort on fixing Steam, making it reliable and 'bullet-proof'. Then release it as an optional service. If it's good, people will quickly adapt it.
Yes, this does prevent you from doing certain things you wanted to dowith Steam, but a dog who chases two rabbits at once will catch neither."