In late December, Valve writer Chet Faliszek stated that an announcement about upcoming Left 4 Dead downloadable content would come "shortly." True to its strangely warped definition of time, Valve finally posted the announcement yesterday afternoon.
As Shacknews reports, the company intends to release the DLC this spring (which may mean some time in the summer). Dubbed the "Survival Pack," the new content bundle will include a third game mode—appropriately titled "survival"—and a couple of new campaigns for the Versus mode. Faliszek said last year that the new Versus campaigns will be Dead Air and Death Toll, which are co-op-only in the retail game.
Also, Valve plans to roll out a Left 4 Dead development toolkit in the spring. The SDK will let players make their own campaigns and maps for the survival-horror zombie shooter, Shacknews says.
In other Left 4 Dead-related news, it looks like Valve has implemented stereoscopic 3D support for hardware other than Nvidia's GeForce 3D Vision. Ars Technica says you can get the game working with 3D glasses from Super Bowl promotions—all you need is a GeForce 8 or better graphics processor, the latest ForceWare drivers, a stereoscopic driver update from Nvidia, and a small registry patch. Check Ars' article for the links and detailed instructions.