Valve's continued release of new maps, character class updates, humorous achievements, and other content for Team Fortress 2 has greatly prolonged the inherent joy derived from hopping into the ranks of red or blue and blowing the crap out scores of other players. However, the spigot has been temporarily tightened, staunching the flow of updated content until next year. You can blame the zombies.

Speaking to Shacknews yesterday, Valve marketing VP Doug Lombardi said the next Team Fortress 2 update won't be released this year. "We're going to keep evolving Team Fortress 2," he said. "Once Left 4 Dead wraps, you'll hear us clamoring more about (the next TF2 update)"

In a post on the official Team Fortress 2 blog last month, software developer Robin Walker explained the team has been moonlighting on Left 4 Dead - Valve's upcoming co-op survival horror, zombie-blasting romp through apocalyptic hell. Unsurprisingly, they've has been helping to complete the game's versus mode, where one teams plays the human survivors and the other plays the zombies.

Here's hoping their attention soon turns back to Team Fortress 2, as the current upgrades for the Medic, Pyro, and the Heavy classes have ushered in many new hours of slaying enjoyment...and sandwich eating.