That's right, AMD are going to boost their reference core clock from 925MHz to 1GHz in order to contend for the single GPU crown. Of course there are already cards shipping with around 1050MHz core clock, and those cards are indeed faster than a reference GTX 680 in some tests, though AMD prefer to make things official.
The cards will launch as "GHz Edition" cards, the same as on their 7870 range of GPUs currently. Most vendors are expected to pick up the range, especially those who typically stick to reference board and cooler design, such as Sapphire and HIS.
When questioned as to why AMD were launching a GHz edition now, and didn't originally, they explained that yields are now better, their average voltage required to hit 925MHz is much lower than it was on early ES revisions, and most chips are happily hitting 1250MHz now. It's time to let the GPU stretch its legs a little as yields improve.
We're excited at the prospect of AMD taking back the performance crown, though still slighly confused as to why they stopped at 1Ghz. Sure, its a nice round number, but 1050MHz would almost guaranteed victory.