Via [url=https://list.valvesoftware.com/]the new HLDS[/url]:
[quote=Valve]
Gameplay:
- Removed random critical hits and "No random critical hits" statistic on all applicable weapons
- Casual matchmaking is no longer in best-of-three format, and now operates on a 45-minute map timer
- Enabled "Extend Map Time" vote menu option in Casual matchmaking
- Decreased Heavy's base health to 250
- fov_desired now defaults to 90

Items:
- Decreased point-blank damage of all Pyro flamethrowers from 13 to 11
- Slightly decreased strength and range of compression blast
- Dalokohs bar now awards +75 HP upon consumption
- The Diamondback now gains mini-crits instead of critical hits, and 15% damage penalty removed
- The Phlogistinator now deals mini-crits when "MMMPH" is activated instead of critical hits

Bugs:
- Fixed bug that delayed stickybomb detonation while switching weapons
- Fixed players appearing to carry multiple weapons at once
- Fixed players sometimes being invisible when recording a demo

Maps:
[b]Badlands[/b]
- Removed intrusive vent at last point spawns
- Improved clipping & hitboxes, closed gaps of spires
- Closed gaps in train car crates and floor of middle control point area

General:
- Updated the localization files
[/quote]
Rumor has it:

- Size is ~230 MB