Eh.. timescales are relative here. Typically when someone around here says “fast takeoff” I assume they mean something along the lines of That Alien Message -- hard takeoff on the order of a literal blink of an eye, which is pure sci-fi bunk. But I find the other extreme parroted by Luke Muehlhauser and Stuart Armstrong and others -- 50 to 100 years -- equally bogus. From the weak inside view my best predictions put the entire project on the order of 1-2 decades, and the critical "takeoff" period measured in months or a few years, depending on the underlying architecture. That's not what most people around here mean by a "fast takeoff", but it is still too fast for meaningful political reaction.