i will be pretty upset if the 7xxx comes out only marginally better for mining. Because i just sold both 5970 at $300 a pop on ebay getting ready for the 7xxx series. Miner is down right now waiting for the new card to release.
Why would you do that? The discussion has been for months that GCN architecture may not be mining friendly.
Your sold 5970s deliver 1.4 to 1.5GH. You do realize that it is a pipe dream to think the 7970 will be ANYWHERE near that. Worse at launch the card is likely going to sell at $549 and even then availability may be difficult.
Disablo may be able to pull some respectable performance out of the card (eventually) but your sale was downright foolish. If the 7970 could someday deliver 500 MH that would be decent. 600 MH+ would be amazing. It isn't going to deliver 1.5GH. You can't optimize something out of nothing.