Valve just announced that tomorrow, Thursday, at 11 am PST (8pm CET) all PC versions of Team Fortress 2 will get the "largest update since the product was first made available on October 10, 2007" (as part of Orange Box). The free update includes...

1. optimizations for networking, graphics and player statistics
2. improvements to Source TV for tournament viewing.
3. performance and gameplay tweaks for Dustbowl, Granary, CTF_Well
4. new map Badlands that "pushes control-point gameplay onto vertical landscapes"

More information on the update (which is delivered automatically via Steam when starting the game from Feb. 14th, 11 am PST) can be found on the official website.