https://twitter.com/DanTwoHundred/status/589109112560099328
Something to look forward to. :)/>/>
Edit:
Since the starting of this thread, some more information has surfaced (mainly through Dan's twitter, but partly through the posts here) as to what this's all about:
Seems Dan's creating a Lua environment similar to that provided by ComputerCraft computers, but as a stand-alone package (outside of Minecraft) and geared towards aiding new programmers in game development. A lot of details are still unknown, though browsing his twitter feed reveals various screenshots and animations of its progress.
While still simulating limitations of older systems in order to inspire a retro theme (eg 4-bit colour depth), new features such as sound, higher display resolution (320x200), and a remappable palette make it more dynamic than what's possible within CC. Tools such as sprite and sound effect editors will be included - the "edit" script will provide different functionality depending on the type of file you point it at.
There is no concrete schedule for release, though Dan has stated that he intends to fully complete development of Redirection first. He's continued to work on COS2.0 since then, however, so anything's possible.
CraftedCart has been maintaining a list of what's been hinted at (along with relevant links), which you can view here.