We don't know many details as yet, but we do know that the card is based on R520 design and likely be called the R580. Knowing ATI, this means that it will end up as a faster version of the chip with faster memory and will be introduced toward Q4.
We are talking about the same number of pipelines, similar specifications, but a faster card. Just bear in mind that the R420, the Radeon X800 series, got its faster brother codenamed R480, X850 generation. It's faster but it's the same card, in principle. This gives some idea of what to expect in the future.
Del med dine venner