The next batch of free content for the PC edition of Team Fortress 2--including the new Goldrush map, unlockable weapons, and Meet the Scout video--is slated to arrive the week of April 20, Valve has informed Shacknews.
Outside of that general timeframe, a specific release date for the new content was not provided.
source: http://www.shacknews.com/onearticle.x/51941
Now lets just hope it doesn't get any delays