Caught that too. This is why I don't trust rumor. How would they release 900/1000MHz stock cards that would require some super binning/factory overvoltage.
From what I heard:
Reference GTX560 Ti card has 822 clock and performs faster than HD6950.
Many AICs have internally tested 900 which will on par with HD6970 and stock GTX570. [Obviously Gigabyte will release such an oc'ed version]
Latest development is that AICs have further tested 1000 and found it to surpass stock GTX570 by 5%. But the biggest news is that the price of such highly factory-overclocked version of GTX560 Ti is around 2000-2100 Yuan only, much lower than price of GTX570. [This is in consistent with the OP's]
So, this means GTX560 Ti will not only affect HD6950/6970 but will also affect reference GTX570. And, as planned, when the inventory of reference GTX570s is cleared by the end of this month, various factory overclocked non-reference versions of GTX570 will appear in the market (eg Gainward Phantom), in order to further separate the GTX570 from the GTX560 Ti.