i think sony will wait a bit to see how much ms gains from price cut, and in meantime try to push more mgs4 bundles with the 80gb on market as a first response.
the fact that these bundles sold like mad might be allready a good counter and enough to avoid loosing too much. best time for a ps price cut will be when the new models come out with the shrinked graphic chip which would probably help them reduce losses of a cut. (so sony will probably will try to wait as long as possible with it)







