if they release the 360 at 400-500$ they might sell off a few units at launch to the dedicated fans who have been waiting, and ati can drop their top end 20% to be a very obvious price/perf winner and attempt to take more market share. so after the nvidia launch effect has faded, they do their price drop to what is reasonable to sell such cards at. and ati will again do a price drop to maintain a slight price/perf advantage, but would probably try to keep higher margins.

i dont expect to see a 200$ 5850 the day a 360 is released, but i bet it will be within 3-4 months of its release. -someone feel free to hold me to that bed, id like to know how close i was