Dude, what is there to not understand seriously? Let me spell it out for you...
1. A GTX280 is effectively a "rehash" of the G92 core based 9800GX2 but instead of having two GPU units on two PCB, they have combined it into one. They have also widened the memory bus to accommodate now combined memory modules that ran as 2x512MB on the GX2.
2. Power consumption and dissipation is about the same if not worse than then current GX2 flagship.
3. Performance is the same. Increases due to drivers are irrelevant because drivers for older cards can be improved too. For kicks I installed your GTX280 driver for my 9600GT and I got a pretty hefty boost in performance, about 10%-15%. But supposedly, 9600GT is not supported by your GTX280 drivers
Do you see something groundbreaking there? I sure don't. And to top it off, the price is stupendously high at $700 per card so unless you have a big ass screen, with a fat ass wallet there is 0 (yes, read zero) justification for buying this card.
There is no doubt that the GTX 280 is the fastest single GPU card on the market.
And no, you don't have to have a fat ass wallet, since most people will be stepping up to the GTX 280. That's justification enough for me. The GTX 280 will no doubt run smoother than the GX2.
I'd say quit bad mouthing the card. Sure, the performance is similar but remember, the GX2 is essentially SLI'd GTS's on 1 PCB, whereas the GTX 280 is a single gpu card. That's pretty impressive in itself.
Read reviews of the GTX 280, it has about 10 times the power of a quad. quads average about 90 Gigaflops while the GTX pushes out something in the midst of ~900 gigaflops. It is no surprise that this will be a folding monster.