Rumor 1:
http://www.dsogaming.com/news/major-leaks-of-radeon-7970s-performance-up-to-60-performance-boost-from-a-gtx580/
7970 offering up to a 60% performance increase over GTX580

My 2 cents:
Probably accurate as the paper launch is 2 days away. If they can keep the prices low like they have the last two generations of cards ($300 range) this will be impressive price/performance wise.


Rumor 2:
http://www.dsogaming.com/news/rumor-nvidia-to-skip-6xx-series-gtx780-to-offer-100-performance-boost-over-gtx580/
Nvidia to skip 6xx series; GTX780 to offer 100% performance boost over GTX580


My 2 cents:
Highly probable. GTX580 was only a rework of the Fermi chip, which was a completely new architecture, making Fermi roughly 2 years old now. nVidia historically offers a doubling of performance between new architectures, so to see them double (or get close to it) with a new card isn't anything that I find surprising (they have done it numerous times before in their history).

What I am REALLY curious about though is whether nVidia will cut back a bit from coming out with these huge power hungry cards that we have seen, and go a bit "cheaper" with more efficient cards like the AMD R5000 and 6000 series. Hopefully they come out at $300-400 instead of $499.

 

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I've seen a rumored price range of $450, $500, and $550 for the 7970 card. Which means I have no idea what it'll cost, but it does seem to be in the upper range. I don't think AMD will be cheap at first, with Nvidia is possibly coming 6 months later with their high end answer.

I think Nvidia is skipping the Geforce 6 series for marketing reasons. They don't want their generation number to be smaller than AMD's generation number.

Which means AMD will follow up the 7970 with a 9970 in 2013.

I am going to hold off on my decision until I see what Nvidia brings to the table. I would really like Nvidia's cards to support tri screen, and I think they have been pushing for it. While I am not against ATI, I would not like to deal with their BS driver problems getting the card stable on windows, or even to work at all on Linux side. Mostly the latter.

 

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Actually as far as the hot and power hungry is concerned AMD is going to follow nVidia into higher TDP's on there flagship cards, also there going with 384bit GDDR5 and they likely wouldn't pull that off unless there going with a 400mm^2 or greater chip. There 7970 and 7950 will be there "GCN" as they call it. 7870/7850 with be die shrinks of the existing 6970/50, and obviously VLIW4.

edit - checked out that site looks like die sice will be 365mm^2 which is fairly impressive if they get those gains. Still pretty big though compared to the 5870's launch if 338mm^2 at 40nm. Hopefully they get some kind of yields.

Something odd that AMD is doing with the 7900 launch is allowing third party PCB designs to be launched at the same time as the reference PCB design. This means we'll be seeing more variety at launch or soon after launch, from cheap PCB designs to high end ones.

Here is one of the custom third party PCBs.
http://www.legitreviews.com/news/12066/