Valve are incorporating the immensely popular Gun Game mod as official modes in Counter-Strike: Global Offensive. Arsenal: Arms Race and Arsenal: Demolition are the two new modes. They'll be playable across eight new maps created with help from the creators of the original mod.
Gun Game replaces Counter-Strike's cash-for-guns system with a kills-for-guns system. Everyone starts with a pistol and gets a new weapon for every kill. Those unfamiliar with Counter-Strike might recognise a very similar mode appearing in Call of Duty: Black Ops, but the original CS mod was the real deal, and it will get official backing when CS:GO is released early next year.
Valve have sent over nine new screenshots, showing some lovely jungle areas. Counter-Strike: Global Offensive doesn't seem to be pushing the Source engine especially hard, but it's a significant step up from Counter-Strike: Source.