i think that the early words from intel were around the 5-10 mark which is kind of where it is (ignoring the pointlessness that is HD4000, or the miracle that is quicksync). I'd class the higher predictions as wishful thinking/fanboyism, this is after all just a die shrink. Those gains for haswell would be realistic thinking.
At 1.52 most processors on 'normal' cooling (and at the clocks that 1.52 allows you to reach) are far to toasty. Time again for peltier assisting cooling (for a different reason), after all the wattage being dissipated isn't that much, its just the low levels thats needed (water will only take you to ambient)