Did I hear that Virgin were going to try it at Gatwick?
Some US carriers were also investigating it for huge and congested places like DFW/ATL/ORD.
Oh, and I think I read in industry magazine "Air Transport World" that another wheeze was to slow traffic down 100-200 miles out to avoid holding. "In search of perpetual motion", I guess.
From an engineering point of view, I'm not sure I'd like to be inside an aircraft that had its engines treated akin to "on-off white goods".
r