What this means overall is EITHER that nvidia's plans to market the 260 at $399 will be scrapped and it will come out at $299 ... OR ... if ATI drops the ball on getting out enough of these cards (which would be FAR from the first time something like that has happened), they'll keep the 260 at or around $399 because they'll be able to count on retailers marking up the scarce but highly desired 4870 to prices around $399.
My bet is on the latter scenario, simply because so often we consumers end up getting f***ed, so I've learned to expect it.
I would also point out that the performance of the 260 on the REALLY challenging benches (vantage extreme, crysis, and yes, lost planet) benches suggest to me that in the long run (meaning future games), the 260 will prove to be a slightly more powerful card overall than the 4870.
There is, of course, another large component of this picture that is missing: OVERCLOCKING. I bet some of you have heard of it? The difference between the two cards is of a scale that it could be easily overcome should it turn out that the 260 is a significantly better overclocker than the 4870. Such a scenario again would be FAR from unprecedented in recent generations betwixt these two competitors.
Bottom line, for $299, this is an amazing card. If ATI can get these out en masse, it'll be awesome, because nvidia will have no choice but to drop prices as well. Were the two cards the same price, personally, despite these results, I'd be inclined to go with the 260 myself. Again, I think it's a more powerful card and I'm betting it'll be an overclocking monster.