The Team Fortress 2 Blog now points to a Classless Update on the upcoming classless update for Team Fortress 2. This will not be a hatless update, as they describe some new hats it will include, and also outline plans for a new map called Arena Offblast:

Arena Offblast is a fast-paced, high-altitude community map set in a top secret missile silo wedged into the top of a hollowed-out mountain. Open-air paths and narrow hallways converge on a central control point located just under the silo’s blast doors.

This mountaintop arena also boasts a sheer cliff face encircling the battleground, giving you the chance to help your opponents improve their tactics. Specifically, anyone you blast over the side will get some time to think about the various flaws in their “standing next to the edge of a cliff” strategy as they plummet to an excruciating, non-respawnable death.