Valve's Robin Walker acknowledged today that they haven't updated Team Fortress 2 much lately. The reason is that much of the game's team is now working on Left 4 Dead 2.

"As with the first Left 4 Dead game, most of the TF2 team has moved over to help out Left 4 Dead 2 get through its final shipping steps," wrote Walker on the Team Fortress 2 blog. "This time around, though, we've improved our process a little to ensure we can keep some people on TF2, enabling us to continue doing TF2 updates."

They haven't completely neglected the game. About a month ago they released a fairly large update with a new game mode and maps. They'll probably start to churn out the remaining class updates (Engineer, Soldier, Demoman) after Left 4 Dead 2's November 17th release.