I know – the bastards.
How dare they do such a thing! Making all the old content work on the new game that’s like, well crazy! Where can I sign a petition to stop this madness of good nature from Valve? OK so I kid but you know someone, somewhere is pissed about this!
Chet Faliszek has told Kikizo the following:
“For modders, everything they make in Left 4 Dead will work in Left 4 Dead 2. It’ll work better if they bring it into Left 4 Dead 2 and recompile it for Left 4 Dead 2, using some of the additions we’ve made, but it’ll work out of the box as well. We just want to make sure that anyone who’s making a mod now knows that their time’s going to be well spent.”
Not 100% sure on teh status of actual Valve DLC but who knows – watch this site fo rmore updates as they come.