Nearly every section of the new Dust 2 map has received visual overhauls that make it a lot more appealing to see. The last game update was October 5, which consisted of small, additional changes to the molotov-smoke bug fix.
CS:GO received its last update earlier this month and it was a pretty minor one. At the time of writing, Valve has not specified a time-frame, but expectations are it will arrive in the next few weeks. You can play the new version of Dust2 right now through CS:GO's beta branch (find out how to do that here). However the most contentious part will be fan consensus on the next map to get a dust off.
Needless to say, the developer posted the tweet to fuel players' interest, and expectedly they started second-guessing what would be the changes Valve has prepared after the hiatus from the Active Duty map pool. The answer is usually Dust II.
What's the first map that Counter-Strike: Global Offensive players usually think of when playing through Valve's 2012 shooter? The map is lighter and brighter throughout, and Valve has removed a series of dark spots where players could camp.
The visual upgrades are also extending to the game's character models, with the Terrorist team getting some higher-resolution models to match the environment.