well let's see history, when I bought my GTX280, it was the creme' de la creme' of graphics cards, one week later, the HD4870x2 comes out and blows mine out of the water! i was angry as hell. then Nvidia retaliated with the GTX285 and 295 and then they were ahead once more.
I have been a green machine supporter all my life, but I have researched the facts, and Nvidia's architecture is not only outdated but seriously flawed, The heat generation and power requirements to run one of its behemoth's mean that the size of the graphics card becomes a factor, (Nvidia tried to compete with the 4870x2 by creating a GTX280x2, it used too much heat, too much power, too much space and so it was that the GTX295 was born, a fabrication running on 2x GTX260's with a few extra processing cores)
ATI has done everything right that it should have done - changed the architecture of the graphics card itself to compete with its rival (we all remember when ATI had those wierd cables behind the case attaching both graphics cards together for crossfire mode), they did a successful die shrink of the GPU (mind you they do have an unfair advantage that their parent company AMD creates processors enabling a more successful die shrink, whereas Nvidia must rely on external company contracts to help compete) They meet the deadline requirements (as seen with DirectX10, they met all the technological specifications, where Nvidia failed, but to make things fair, Microsoft relented to Nvidia's objections and because of this, DirectX10 didnt look nearly as good as it was supposed to. ATI's first DX10 cards had certain useless components in them because of this because they met the specifications of the DX10 API and Nvidia didnt) and they are recognised by many in the industry as a good company (ATI has the next gen's consoles graphics pick with Xbox and Wii both backing them for their next consoles to be released later than 2011 and Intel getting sony's PS4 contract with their Larrabee)
Now with direct X11 looming around the corner, if ATI chooses to increase the speed of its GPU's now that they have successfully managed the die-shrink, up the shader clocks, (they already have enough stream processors). We will see the likes of ATI that Nvidia will need a miracle to overcome