Of course a price-cut would increase demand for the PS3.
However, a Sony will have to find a way to decrease the price of production first..
With the increase in production from the Europe launch, and its newer better games coming out, and the hopeful implementation of HOME, if they can increase monthly production enough, it might happen sooner than later. I am basing this on the fact that it is cheaper for a factory to operate at 80% capacity than say 50%.
65nm, cheaper heads (courtesy of Pioneer or someone producing over volume), cheaper blu-ray laser diodes (which is already happening because of increased production by Pioneer, Samsung, etc on Blu-ray players), and the removal of the emotion chip.
Sony is already on course to bring the parts cost down by 100 dollars by the middle of this year.