The Team Fortress 2 website has details on changes coming to Team Fortress 2 in an upcoming patch for Valve's team-based shooter. They describe fixes coming to several maps to close off bugs and exploits, many of which have been caused by the introduction of new weapons over the years. They also have word on new maps being added to the rotation. Here's a bit:

And Badwater is just one of the maps with fixes in this update. In fact, the majority of maps in TF2 have gone through the same process. By eliminating these exploits and bugs, players can once again feel like they understand threats and the dangers presented in combat spaces.

Secondly: Sure, it’s great to fix the old maps, but we’re also adding two NEW community-created maps by Ian Cuslidge that, and here's another spoiler warning, are fricking awesome. Introducing two all-new Capture Point maps: Process and Standin. Beyond a great polish, both of these maps offer unique and exciting gameplay; Process with its five streamlined Capture Points and Standin with its triple Cap Point free-for-all.