The update includes a new map - Koth Harvest - which features a ghost that can scare players to death. (Their in game characters....not the actual players of course)
It also includes new hats and pumpkins that can be collected for prizes. Naturally, there are new achievements to go along with the spooooky themes. They are:
Candy Coroner: Collect 20 Halloween pumpkins from dead players to unlock a hat.
Ghastly Gibus Grab: Dominate a player wearing the Ghastly Gibus to earn your own.
Scared Stiff: Kill a player scared by the ghost haunting KOTH Harvest.
Attack O' Lantern: Cause the deaths of 5 players by exploding nearby pumpkin bombs.
Costume Contest: Kill a Spy disguised as your current class.
This may only be a small treat but its a nice one - especially when most of the Team Fortress 2 are working on the even more Haloween appropriate Left 4 Dead 2
Have a spook-tacular time kids!
(Originally written for Game-Debate)