These might've been the quickest price cuts, but they were also the most predictable price cuts ever... Even nVidia saw, after it was too late to go back and change their designs, that they were very liable to be in for a beating. The cards performed as most mainstream predictions foretold, and as well as AMD designed and predicted; the 4870 fell between the GTX 260, and the 4850 bested the G80/G92 parts.
It was pretty much a given that at the original price, the GTX 260 utterly lost all reason to exist, and the GTX 280, offering only a tad more performance than the 4870, could hardly argue it being worth more than twice the price, especially with a dual-GPU version of the 4870 on the way that would've been cheaper as well.
So really, It was a matter that nVidia was going to lose either profits or market share. As standard decision-making goes in the market, they opted to sacrifice profits... With them now making perhaps next to nothing on the GTX 260/280 cards.
Really, dealing with the technology market, it does take a bit of education to be able to properly and accurately predict what will happen. But this time, yes, people were able to predict things. A lot of them predicted wrong, because they lacked prior knowledge and education... As a lot of people mention, they've only had their heads in the GPU field for the past couple years ago, so they've never seen anything like this, while a few of us were around to remember a similar case when the Radeon 9700pro came out against the GeForce 4 Ti.