Yes, today Left 4 Dead players get their long awaited DLC in the form of the Survival Pack, which adds Dead Air and Death Toll to the Versus Modes, plus the new Survival Mode. As always this content is free for PC gamers but in an additionally cool move by Valve, this DLC is also free for XBOX LIVE players.

Still no concrete release on the SDK for PC gamers, but that has not seemed to stop fans from modding the game anyway. Presumably the SDK will be out today and we’ll post more on that as information arises.