Seriously, who in the HELL was EXPECTING this card to be able to trounce a GX2? I mean, COME ON. That's TWO friggin cards against one, basically! The fact that it even comes close in some cases, and isn't THAT far behind in any case, means that this is one impressive chip/architecture. Is it worth the cost on a p/p ratio vs a GX2? Obviously not, at least, not with the current drivers.
I think everyone's become a bit spoiled by their expectations with new chip generations ever since the 8800GTX came out. That kind of advancement was 5 years in the making, it was a 'once in a decade' kind of performance improvement. You look at ANY other generation in the last 10 years (and believe me, I've watched all of them) and you will NOT see a jump like the 7900GTX to the 8800GTX apart from that jump.
And furthermore, the card that this should be most fairly compared to is NOT the GX2, but rather the 8800GTX, which this chip is the true successor to.
As an example, remember when the 7800GTX 256MB came out (original top of the line of it's generation), it was $500, and it was nowhere NEAR as much better than the 6800 Ultra as this new GTX280 is vs. the 8800GTX, which is itself a friggin MONSTER to this day. But people were impressed, and they bought lots of them (along w/the 7800GT).
I think people's expectations are way out of whack if they expect this SINGLE GPU solution to be able to beat out a THREE MONTH OLD top of the line DUAL GPU card!
Bottom-line, I expect these prices to come down and more into line with it's real price/perf ratio. And for the GX2 to be going away very soon.