Haha, people are complaining about Valve?
Do you guys have insanely high standards or what? Seriously, I don't know any other company besides maybe Blizzard who go out of their way with free updates and such.
They've already patched up TF2 to reduced the 'headaches' of the unlock system: Now you can do both achievement milestones or by random chance. Item trading will also be implemented soon in the future, so if you SOMEHOW don't have the items yet, you'll get your chance.
As for L4D2, I do agree it was too soon to announced a sequel, but people act like Valve just abandoned L4D 1. In previews/interviews, they said they were still going to support the original L4D, and they said they want to find a way to allow both games to be played without having to exit/switch CD's/etc.
I think it's more likely Microsoft pushed them to announced L4D 2 so early. Correct me if I'm wrong though.
Considering all the free updates they've given us before (TF2 is a great example of this), plus fan service and some serious community spirit, they're not worth complaining about. Yeah, Episode 3 is taking forever, but hey...I've seen worse. (Starcraft 2 anyone? 11 years man and still going!)