Embedded components could definitely be a benefit. This sort of thing is already somewhat possible (e.g. PCB cavities) but has limitations. Another interesting

Embedded components could definitely be a benefit. This sort of thing is already somewhat possible (e.g. PCB cavities) but has limitations. Another interesting possibility would be designing complex surfaces that components can attach to rather than the traditional top/bottom of a PCB. Again this is already somewhat possible with techniques like 3D-MIDs (molded interconnect devices). 3D printing would make this sort of thing far more feasible though as MIDs are inherently limited to traces on the surface, meaning you're limited to a single layer. Pick and place machines would need to get rather advanced for this to work as well. I know there are a few out there to handle MID orientations, solder paste extrusion, and laser soldering, but from what I've seen they're quite slow. Of course heat dissipation and electromagnetic effects could become interesting design challenges (or design patterns) if the geometries are complex enough.