This could be a major advance if it holds its promise and finds widespread adoption:
tl;dr: A team of researchers at University of Washington have developped a method of manufacturing PCBs using a form of epoxy to bind the fibreglass that can be un-cured and re-cured as often as you like. So instead of incineration, often in 3rd world countries in very unhealthy conditions, you can unsolder all the components, disolve the copper then return the board to un-cured resin plus glass fibe, both reusable!
I guess it might take a bit of legislative pressure similar to RoHS to push it forward.