Via [url=https://steamcommunity.com/games/CSGO/announcements/detail/529846144626327636]the Steam Community[/url]:

[quote=Valve][b][u]MISSIONS[/u][/b]
- Added Weekly Missions, which can be entered though the main menu or play menu.
- Players receive one mission each week.
- The weekly mission expires after 7 days and rewards XP for completion.

[b][u]MAPS[/u][/b]
- Removed community maps Basalt, Edin, Palais, and Whistle from all game modes.
- Added community maps Jura, Grail, and Agency to Competitive, Casual, and Deathmatch modes.
- Added community maps Dogtown and Brewery to Wingman mode.

- Re-organized Casual and Deathmatch map groups.
- Defusal Group Alpha: Dust 2, Mirage, Inferno, Vertigo.
- Defusal Group Delta: Train, Anubis, Ancient, Overpass, Nuke.
- Community Map Group: Jura, Grail, Agency.
- Hostage Group: Office, Italy.

[b][u]AUDIO[/u][/b]
- Added "Main Menu Ambience Volume" setting.
- Fixed some cases where shooting visible enemies over the top of smoke would not play an attacker feedback sound.
- Fixed some cases where gameplay sounds were inaudible or would skip.
- Removed snd_setmixer, snd_setmixlayer, snd_soundmixer_setmixlayer_amount, and snd_soundmixer_set_trigger_factor console commands.

[b][u]MISC[/u][/b]
- Fixed a bug where input bindings to scancode56 (US English key "/") wouldn't persist across app launches.
- Lobby invites from players marked with "Block All Communication" in Steam will now be ignored in-game.[/quote]

Rumor has it:

- [b]Size is close to 5 GB (with Workshop Tools installed) - data capped users should take action NOW![/b]