Yeah, I agree with Que. The only reason I paid full price for L4D was for the possibility of expansion with added campaigns, maps, community content etc. I'm not paying an extra dime to get something I am entitled to as a paying customer.
I know some of us gamers get an overactive sense of entitlement from time to time, but in the case of L4D the game's release state is sub par.. I'm not talking about technical quality, but content. Let's see, what does L4D offer: 4 areas, each with 5 maps, and 2 Versus maps.. that's it. And Valve's response to players' complaints was "more content will come soon!"
The same thing happened with Team Fortress 2, it initially only came out with 2 maps, 2 weeks later 2 more maps were included in the auto-update, then some more.
The Survival pack had better be free for current owners, oh I'm sorry, licence registrees of L4D.