A post by Valve's Adrian Finol to the
Steam Users Forums (thanks MonkeyBrains) reveals that Half-Life 2 deathmatch
is the surprise announcement they recently hinted about (story).
The post simply links to this
image, which says the proverbial thousand words about our upcoming
opportunity to throw more than just the kitchen sink at each other.
It is a screenshot... Probably taken at a high resolution and scaled down. I suspect this because you can easily see jaggies on the female models leg, around the air conditioning ducts, and in the right corner of the room where the walls meet.
That doesn't mean it's in-game. I think it's very obviously not. It's either a render from a 3d app or a heavily edited screenshot. I don't think that matters in any case.