Via [url=https://list.valvesoftware.com/cgi-bin/mailman/listinfo/hlds]HLDS[/url]:

[quote=Valve][B][U]Scream Fortress VII has arrived![/U][/B]
- Comic and additional information available on the website ([url]http://www.teamfortress.com/screamfortress7[/url])
- Featuring 4 community maps: Gorge Event, Sinshine, Moonshine Event, and Hellstone
- Added the Gargoyle Case which contains 19 community made cosmetics
- Added two new community-made taunts to the Mann Co Store: Soldier's Requiem and Zoomin' Broom
- Collect the souls of dead players for your Gargoyle by killing enemies, doing map objectives, or collecting the Soul Gargoyles that spawn in the maps
- Scream Fortress VII runs through November 11th, 2015

[B][U]During Scream Fortress VII[/U][/B]
- All players who launch the game will receive a Gargoyle
- Gives access to Merasmissions and Halloween item transmutations
- Tracks Merasmissions completed and souls collected
- Added Merasmissions
- A new Merasmission will be available daily up to a total of 13
- Completing a Merasmission will give players a classic Halloween item and a chance of the Gargoyle Case
- Added Halloween Transmuting
- Transmuting can be accessed by clicking the Gargoyle in your backpack and selecting Halloween Transmute from the context menu
- Players can transmute 3 qualifying items to receive a non-tradable classic Halloween item. A bonus item will be given for every 10th transmute.
- Mann Co Supply Crates will have a chance for a classic Halloween Unusual effect

[B][U]General[/U][/B]
- Added inspect animations for the Batsaber and the Giger Counter
- Fixed an idle animation bug for the Wrangler
- Lowered the speed penalty for getting stunned by a ghost from 50% to 25%
- Lowered damage of the "bats" spell from 60 to 40
- HHH's axe has dulled a bit and no longer guarantees death, but is still very lethal
- Fixed an exploit related to picking up The Widowmaker
- Fixed the Batsaber not showing the Killstreak sheen
- Fixed a scoreboard stat reset bug in Mann vs. Machine
- Optimized texture memory usage
- Fix some cases of random hitching experienced by some players
- Fixed overhead icons stacking on top of each other and now appear side-by-side
- Added "Sort by Date" to the backpack. Newest acquired or altered items are sorted to the front.
- Cosmetics that have Rarity and are part of a collection no longer show a cosmetic item level
- Fixed the buildcubemaps command failing to update cubemaps for maps that already have cubemaps
- Fixed a case where running the game with -buildcubemaps would generate all black cubemaps
- Updated cp_powerhouse to fix a couple places where players could stand on top of doorways
- Updated The Infernal Impaler, L'homme Burglerre, The Spooky Shoes, The Spooky Sleeves, Cuban Bristle Crisis, The Grimm Hatt, Medi-Mask, The Bearded Bombardier, The Colonel's Coat, The Killer's Kit, The Vascular Vestment, The Physician's Protector, The Cold Killer, The Courtier's Collar, The Physician's Procedure Mask, The War Pig, Respectless Robo-Glove, Insulated Inventor, The Dry Gulch Gulp and The Minsk Beef with the latest changes from the authors
- Updated koth_probed
- Improved optimization of map (especially on mid)
- Fixed clipping issues (thanks Muselk!)
- Fixed Engineer imbalance on mid (thanks Uncle Dane!)
- Added in missing explosion sound effect on aliens
- Fixed a few prop/ material issues
- Reduced prop usage

[B][U]PASS Time update[/U][/B]

- Fixed viewmodel/worldmodel when tf_passtime_ball_model is set
- Added convar: tf_passtime_ball_sphere_collision
- Added entity: tf_logic_on_holiday

[B][U]Mannpower update[/U][/B]
- No longer in Beta
- Added new map: Hellfire
- Three new powerups: King, Plague, Supernova
- Grappling hook changes
- Reduced max rope distance
- Reduced grapple dismount jump height
- 30% hook movement speed penalty for Heavyweapons
- Flag rule changes
- Flags can no longer be returned by touching them
- When dropped, flags return after a timeout. This timeout does NOT reset if the flag is picked up again before it returns or is captured
- 25% hook movement speed penalty for powered up flag carriers (with the exception of Agility)
- Small health regeneration for non-powered up flag carriers
- Flags and capture zones are disabled for 30 seconds after a capture
- Powerup rule changes
- When killed, your powerup will drop as the enemy team color. Deliberately dropped powerups are neutral colored
- You cannot pick up enemy colored powerups
- Team colored powerups will attempt to respawn in that team's base if not picked up in time
- Other changes
- Overhead powerup icons are now team colored
- Warlock powerup renamed to Reflect
- Reduced Knockout max health bonus for demos carrying swords and shields
- Haste now increases huntsman firing speed
- Bug fixes
- Reflect damage no longer occurs after death (Pyro afterburn)[/quote]

Rumor has it:

- HUD resource file updates and VPK contents diff: [url]https://github.com/SteamDatabase/GameTracking/commit/fa6560556aa183dd615f80565359223f51116537[/url]
- Custom HUDs can and likely will break in some fashion after this update

- Here's the large item schema update: [url]https://github.com/SteamDatabase/SteamTracking/commit/f6e43ea9bdc1a78dedf4eea999fe54f93e825ca8.diff[/url]

- A small amount of competitive matchmaking piping was added in addition to GC protobufs for Scream Fortress: [url]https://github.com/SteamDatabase/GameTracking/commit/1166da08674667200736b5974e2df58c36300252[/url]

- Size is close to 500 MB - [B]data capped users should be on alert[/B]