As FormLabs have shown, Fused Deposition Modelling in which a filament of plastic is extruded layer by layer to make up a 3D Print, is not the most fine-grained approach. Compared to stereolithography FDM is positively rough. Even on the most expensive printers it is possible to see the grain created by each layer, and it is quite marked on the low-end printers. But "grain" may be just what the average Maker wants if they are printing in wood.
Yes, it is now possible to source FDM filament with wood as the primary material. The new material, called LAYWOO-D3 is made from 40% recycled wood, along with binding polymers to hold it together. It’s loaded into a 3D printer as a thin filament, and when printing is complete, it forms a wooden surface not dissimilar from MDF Medium-Density Fiberboard.
The supplier says that LAYWOO-D3 "Allows you to print wooden-like objects with annual rings." I think future refinements of such a material will appeal to many Makers, especially if it can take a polished surface.