Zombie details revealed!

Via TheVerge.com

"One of the things our community has told us is that the love the game but they want to play it in different ways," said Treyarch studio head Mark Lamia at a press event this week. In addition to classic Survival mode, in which players will fend off waves of undead, two additional Zombies modes will ship with Black Ops 2.
Tranzit is Zombies' new story-based campaign set in an "expansive world" for players to explore. "It's massive," Lamia said, describing an open area game world with interconnected zones. Players will have access to transportation, the fortified bus seen in Zombies mode's first trailer, to travel from map to map. The bus provides players with shelter, Treyarch says, "but it's also a confined space, so it comes with its own issues." Players will be able to fight on the bus as it transports the team. They'll also be able to get off the anti-zombie bus, "go out into the fog" to explore, and search for items and new dangers.
Lamia said Tranzit mode will feature player-created items, "buildables" that can be used as weapons or a means of defense. Black Ops 2 Zombies' new trailer shows DIY assault shields, which like their Black Ops 2 multiplayer equivalents, can be planted to provide mobile cover.
In Tranzit, players will be able to piece together the cooperative multiplayer mode's storytelling. Lamia hinted that the plot of Zombies mode in Black Ops 2 will tie back into the fiction of the Moon map released last year for the original Call of Duty: Black Ops."If you played 'Moon,' the actions you had there may have had some impact on what happens in Black Ops 2 Zombies," Lamia said, implying that players will be battling the undead in a post-apocalyptic world borne by decisions from Treyarch's previous Zombies mode.
Also new is Grief, a new competitive mode that pits humans versus humans versus zombies — nicknamed "4z4" mode by Lamia — in a last team standing battle for survival. In Grief, players can't directly shoot each other to kill the opposing team, Lamia says. Only zombies can take out a team of humans.
"But you can make their lives harder," he teased, adding that the mode is built on the foundation of "griefing" player-harassment game mechanics that give it its name.
Grief will be playable in matches of two to eight players in various team-sizes. As in Survival, players will control teams comprised of agents from two United States government agencies: the CIA and CDC. The four playable characters seen in Tranzit appear to be unique to that game mode.
Treyarch says it will implement features of Black Ops 2's standard multiplayer into Zombies competitive and cooperative modes, including skill-based matchmaking and custom game options. Custom Zombies games will permit players to choose their starting round, opt for a headshots-only difficulty challenge, and disable magic items (Pack-A-Punch vending machines, mystery boxes, perks).