Don't really see what AMD is trying to achieve with this, considering even if they released a new card that's slightly faster and cheaper than the GTX780Ti, majority of the people would still rather spend a bit more money getting the GTX780Ti instead (similar to 290 vs GTX780); if the new AMD card is priced higher than the GTX780Ti, it is not going to shift.
So again, I don't know what AMD's thinking.
If its faster and cheaper than the TI a lot will buy it. if its a fair chunk faster and slightly more expensive still a lot will buy it.
290X's got a crap start really in the press etc with the cooler (which i think we all agree was not the best) And the press sample thing aswell and the revised fan speed( sorry mud sticks even if its not true(
If AMD have a good cooler and a good card at a reasonable price at launch it will sell dont worry