Recently, Oxeye dev thewreck had quite a bit to say on the current and future development of Cobalt, covering a wide variety of topics including Adventure Mode (which includes a lot of new features, including but not limited to some pretty sweet lighting improvements, and procedural generation), item comparison, and more! Click the image above (or this link) to read all the juicy details!
A brief excerpt on the lighting engine:
You need contrasts and varying moods. To achieve this we had to work on improving the lighting of the game. One component is that it is now possible to render most common tiles with individual colors for each corner. Then, we let lights affect those colors. Left light is only using the shader, while the right light is also affecting tile corner colors. Having this we could now create really dark areas, while still being able to light them up nicely for contrast.