Many, in fact most of the novel new ideas spoken of in news and trade articles have been around for decades and were never implemented. When the underlying circumstances finally change, an old idea often receives fresh attention. Prop-pusher airliners have been around for years (Boeing UDF) but were never made because oil was too cheap to justify it. We can safely predict such a design will see the light of production now perhaps as a replacement for the 737. The saucer shaped UAV shows a renewed interest in designs that are also pretty old. Round designs were fielded in the years shortly after WWII. Now they are again current because of changing war tactics in Iraq and Afghanstan, the need for tighter border control and the invention of microchips that allow unstable aircraft design.