We've been following the folks at Open3DP for a while now as they proceed through experiments in 3D Printing. Lately they've been working on perfecting printing molds that have revolutionized the production of RepRap Prusa Mendel 3D printer parts. However, we now see they're working on an entirely new project: an inexpensive, presumably open-source powder-based 3D printer.
Their video shows a very early experiment, and while the result is modest, the direction is clear. They're making a printer that could enable hobbyists to produce new kinds of objects with a different technology.
How different? The big difference with powder printing is that it by default acts as it's own support material. Layer-by-layer printing occurs, but each layer can be printed on undisturbed powder below. This means that whole new classes of 3D objects can be printed, especially those requiring difficult support structures when printed on "normal" extrusion-based hobbyist 3D printers.
Another possibility is that some of the companies currently based on or directly marketing open source personal manufacturing equipment (e.g. MakerBot, BotMill, etc.) might eventually consider adding this type of equipment to their product lines. However, we see one tricky problem: printing in powder is incredibly messy, and really requires dedicated equipment to vacuum up the residue as well as cleaning and finishing the printed object. Likely such a printer might not be successful unless accompanied by appropriate finishing equipment.
There's not much information available in their post other than "We would like to share something we made", but this looks very interesting, indeed. We're watching for further developments.