The Mojang site has been updated with a new downloadable snapshot of the next big Minecraft update. The build includes a few features that lead developer Jeb teased on twitter recently , including trading villagers and new currency items. The update list also mentions a "new useful block/item," sandstone stairs and a bunch of smaller fixes.
The folks on the Minecraft wiki have identified the new block as an Ender Chest that can be crafted using an Ender Eye and eight Obsidian blocks. It'll store your stuff, like any chest, but anything stashed in an Ender chest can be accessed through another Ender wherever it is, like those inexplicable magic boxes in Resident Evil.