After successfully climbing Mount Everest, DayZ creator Dean "Rocket" Hall has revealed to Gamasutra
) in a recent interview that the standalone title currently under-development is operating in "closed alpha", with roughly 50-100 people hand-selected from various sources. Hall also revealed details on the new pricing model for the zombie survival title that once began as an ArmA 2 mod.
So what we're doing at the moment is, we gave free keys as a gift to the forum moderators, the Reddit moderators, people who helped out with DayZ development, and stuff like that. I guess there's about 30-100 people involved with that.
People pay X amount of dollars and they get early, cheap access to it, and then once it's beta, price goes up, maybe, say, $10, and once it goes retail, the price goes up $10.
Hall also confirmed that the game will not be released in alpha mode earlier than June, stating that "once we've finished our server/client architecture" the situation will be reviewed as to when alpha will become available in June.
The DayZ standalone was initially expected to launch at the end of 2012, however was pushed back due to further polishing and content addition. For more information on the process of DayZ including risks and challenges check out the full interview at Gamasutra.