Steam has another new automatic update for Left 4 Dead. The new version of the co-op shooter introduces fatigue to the melee attack in versus mode and Boomer vomit will now pass through common infected. The update also fixes some bugs in the client as well as the dedicated server. Meanwhile, the Left 4 Dead Blog explains the changes and outlines future plans for the PC and Xbox 360 editions of the game:

We recently updated the PC version of Left 4 Dead with some exploit fixes and Versus balancing. We are going to be releasing another small update later today that contains some server issue fixes and one small, but very large, gameplay adjustment. We have made a change to the melee mechanic in Versus and the soon-to-be-released Survival Mode.

Xbox 360 users will see these same gameplay changes in an update coming out with the DLC — which, in case you missed the announcement, will be coming out April 21st.

As we continue to work on Left 4 Dead, our plan is to release more frequently on the PC, and then group those updates for the 360.

With the upcoming release of the SDK, and the community servers already available on the PC, matchmaking is one place where the two platforms will diverge. A future blog post will detail our roadmap for PC matchmaking.

Game statistics help us evaluate the success of the changes we've made to the game. In Versus, for example, we flipped the order in which teams play the next round based on who was winning the round before it. We were confident this would help to better balance the game and give neither team a lasting advantage. That would, in turn, translate into more people playing through the final maps. Since making that change, we've noticed the percentage of games being played to the end jump 5%. It is a small increase, but a step in the right direction.

But statistics are only part of the picture. We also use direct feedback from players themselves. One of the questions people ask is if we read the forums: the answer is yes. So please post your feedback on the melee and other changes as we make them. We promise to keep listening to your feedback, making changes and improving the gameplay experience of Left 4 Dead. Remember: If you don't see an issue addressed with this update, that doesn't mean it isn't coming.