While DayZ creator Dean Hall originally wanted to get the standalone release out before the end of 2012, that clearly hasn't happened. Citing the ambitious nature of "redeveloping the engine and making the game the way we all dreamed it could be," he writes that a closed beta test will be ready soon for 500-1000 people to help test the new architecture. Once finished and the obligatory fixes have been made, there will be a new internal date for public launch.
Elsewhere in the blog post, Hall talks up the overhauled inventory system in DayZ Standalone. "You scavenge for items now, as individual parts, picking up pieces rather than piles, looking for cans on shelves or under beds," he continues. "The new system opens the door for durability of items, disease tracking (cholera lingering on clothes a player wears…), batteries, addon components, and much more. If you shoot a player in the head to take his night vision, you will damage the night vision."
Additionally, Hall explains that the team wants a user interface that is "simple and effective, rather than flashy and complex." While there aren't images of this yet, they were "greatly inspired by Minecraft." There are, however, some miscellaneous new screenshots of Chernarus. Follow the aforementioned link to check those out.