Arrgh - can't sleep....... lying in bed thinking of refresh rates and what Mark said.
I think that 50Hz (PAL) or 60Hz (NTSC) input signal to the tv is fine for flicker free viewing. In fact - movies are shot @ 24fps, and blu-ray players can output to the tv at just
24Hz though a HDMI cable.
LCD's don't naturally produce flicker like CRT's do, but the shutterglasses
will produce flicker. Therefore the shutterglasses will need to operate at 60Hz per eye - which means that the tv output will need to be 120Hz.
Computers are different. Computer monitors won't take an input signal from a 3D video card and apply logic to it to create a flicker free experience - so you need a 120Hz input to match the 120Hz output. Tv's, however, will apply some logic to convert the input signal to an appropriate output display - it's why we have 100Hz and 200Hz displays for out 24Hz or 50Hz inputs.
The important thing for 3D tv is how the tv handles the 50Hz input signal and converts it to a 120Hz output
Disclaimer: It's late, so if any of this is trash and not true I have my excuse