Don't get too excited if you start seeing some desktops offering the new AMD Radeon HD 6700-series graphics cards. That's because the company has taken the all-too-familiar tactic of just giving the Radeon HD 5700 lineup the new name.
As Hexus.net points out, all of the new Radeon HD 6000-series of cards are based on the 5000 parts, but the HD 6800 and 6900 cards have been tweaked to deliver improved performance. It doesn't look like that with the 6700 boards, which have the same number of stream processors and the same memory bandwidth as their 5700 predecessors.
The good news is that the Radeon HD 6770 (pictured above) and 6750 won't be available as retail cards. These will only be available to OEM manufacturers. Of course, you might see them in systems from these manufacturers if you're PC shopping, so just be warned that you're getting neither new nor improved with these graphics cards.