No doubt in honor of this weekend's DOTA 2 International Championship, Valve is now offering there new DOTA 2 hats in Team Fortress 2.
Available are: The begoggled Clockwerk hat, the Raidenesque (or really Storm Spiritesque) Storm Spirit Hat, and the Sniper hat, which is a lot like the goggles from Clockwerk but without the super-sweet jaw attachment. (Update: It looks as though the hats may only be available to those who participated in the tournament. Alas.)
DOTA 2 Hats for Team Fortress 2 [Natural Creeps]