The canaries are singing that 12 pipelines, 475MHz/950MHz card with 96 bit precision and PS 2.0 shader only will end up faster then 16 pipelines, 400MHz /1100MHz cards with 128 bit precision and PS 3.0 shader model.The R400 card (now renamed to R500) has support for all these features but this card with 128 bit precision and PS 3.0 is postphoned to later this year.
ATI knew for some time it would lose out feature wise, but stays committed to bring the faster technology, without some of the extra features.
But there are also rumours that NVIDIA has some faster NV40 chips which they are saving for later.
Source: The Inquirer