I would like to see some Scythe fans that are thermal-controlled with a long sensor wire. It can be done.....I have some 120mm Globe fans like this. The problem with the Globe fans is the temperature curve.......the sensor has to reach 70C to ramp up to 12V.
A useful temperature curve would be 5V @28C, ramping up to 12V @45C. You could place the sensor in a spot that actually would reach 45C (such as the CPU area). You could design an adjustment ability for the temp curve.....something like the Antec fans with their fan speed adjustment dongle.
I'd gladly pay the higher price for such a "super-fan".