Edit: @ TGGA: ^ Yep but then again, there was the thing about investors being angry with ATI's low prices of the 4850s and 4870s. They felt that ATI could be making more money on them...which is probably true but it is funny since they are choking NV. I think the angry investors will affect the x2 pricing a bit. I wouldn't be surprised if it only drops by a small amount. Just my opinion though.
Oh, I agree, I think I said even before they launched that I think ATi had overestimated the gTX series and under priced their HD4Ks leaving a ton of money on the table where they likely could easily have charged $50 more per 4850 and 4870 without changing the market place much more other than making the equilibrium price a little higher and reducing a bit of the shortages.
Even driving down the GTX price is only so effective a tactic, because really AMD doesn't need to try and inflict more damages on nV (they seem more than willing to do that to themselves with the whole mobile and mobo issues), what AMD needed to do was to improve their margins as much as possible and help make their balance sheet more of a plus than a minus. I definitely think that ATi sold themselves short on the HD4870, the only problem is that it won't only affect the current round, but with the improved Xfire and SLi support, justifying the return to $600 cards is going to be very difficult with solid $200-250 single cards.
Which is why it's not just about the X2 vs GTX280, but the X2 vs two HD4870 and two GTX260.