They absolutely dont need to release a 1200mhz card... a 1050-1100 will not be a problem, 1100mhz is easy to do with no voltage increase using CCC . ( max is 1125mhz in CCC and i have yet to see a card who was not stable at this speed. )
Outside difference in some specification ( turbo, size and some features ) clock to clock, i think we have never get an Nvidia and AMD card so close of each other.
Edit:
I have make a little compilation between the 680 vs Asus DirectCU II ( 1000mhz / 5600mhz ) 1900x1200 based on Guru3d reviews for both 680 and Asus DirectCU II ( for an unkown reason he have not put the 680 results in the DirectCUII reviews ( who should have been made after his 680 review )
( i dont put FC2 and MW2 this bring no difference there )
Anno2040:
- GTX 680: 119fps
- HD 7970: 122fps
- 7970 1ghz:
129fps
Anno2070:
- GTX 680: 87 ( 1600p= 55fps )
- HD 7970: 82 ( 1600p= 55fps )
- 7970 1ghz:
87fps ( 58fps 2560x1600 )
Metro2033:
- GTX 680: 39fps
- HD 7970: 44fps
- 7970 1ghz:
45fps
Cryis2: ( 7970 allready win at 2560x1600)
- GTX 680: 63fps
- HD 7970: 61fps
- 7970 1ghz:
66fps
BF3: ( 7970 stock is faster without FXAA of the 680 )
- GTX 680: 57fps ( 1600P 38fps )
- HD 7970: 46fps ( 1600P 34fps )
- 7970 1ghz:
51fps ( 1600P 36fps )
AVP DX11:
- GTX 680: 52fps
- HD 7970: 55fps
- 7970 1ghz:
61fps
LP2: ( testB )
- GTX 680: 54fps
- HD 7970: 44fps
- 7970 1ghz:
46fps
Dirt3 will be a pure win for the 680, but i dont have the numbers.
Asus 7970 review
http://www.guru3d.com/article/asus-radeon-hd-7970-directcu-ii-review/22
GTX680 review
http://www.guru3d.com/article/geforce-gtx-680-review/24
Looking at these result, i dont think AMD will really release another card. This is just a 1000mhz 7970 .. I dont even see why AIB would decrease their price. They just have to release different OC models.