Will this reflex the price of the 7970 you believe ?
10-20% isn't much faster so either this card retails for like $650+ or it takes the 7970 price and the 7970 sits back seat around $350-$400 and the 7950 sits around $300 maybe?
Remember that GK104, which will launch soon, will force prices down. If it ends up being the same speed as Tahiti XT, expect prices for the 7970 to only go down to $500 or so because NVIDIA won't launch a card that's faster than the GTX 680 for more than half a year. Now, if it ends up being 10-15% faster than the 7970, expect the 7970 to go down to $400-450.
As far as the other cards go, I expect we'll see more competition there. I wouldn't be surprised if lower-tier GK104 cards means we get to see the HD 7950 at $350-400, the HD 7870 at $250-280, and the HD 7850 at $200-230. If there's a price spread like the one above ($100 between the 7950 and 7870), AMD could can launch a 1.5GB HD 7950 at $300-330 and/or an HD 7890 at $270-300.
Everything depends on how much NVIDIA forces prices down, which they probably will. That's good, because I can get an AMD card much cheaper than I normally would have.