IT seems that AMD is copying a technique from Nvidia and creating a new graphics chip from an old one just by changing the packaging.
Zdnet claims that the new AMD Radeon HD 6700-series graphics cards is the Radeon HD 5700 in drag
The Radeon HD 6000-series of cards is based on the 5000 parts, the only thing different is that the HD 6800 and 6900 cards have been tweaked to deliver improved performance. The 6700 boards, which have the same number of stream processors and the same memory bandwidth as their 5700 predecessors so nothing to see there move on.
It is not as if AMD is trying to con the great unwashed with its marketing move. The Radeon HD 6770 and 6750 won't be available as retail cards and will only be sold to OEMs.
OEMs should know better, but in case some dodgy sales person tries to convince you that the later series is new and improved you have been warned.
Rebadging is jolly annoying for the consumer, but really good for the manufacturer which looks to be on the ball and producing lots of new chips, when it isn't. It is a triumph of marketing over substance that they ever get away with it
This time though, it was actually on AMD's roadmap, they already told the Juniper chip was to stay a while. Probably this has something to do with the 32 nm stuff up, and AMD not seeing the benefits of making all new low end products if the old ones are still more than competitive.
It has to be said though, they didn't take actual HD 5770 cards and put them in a new box: the HD6770 features HDMI 1.4, while the HD5770 doesn't. It still doesn't justify the new generation name of course (unless we go by nVidia's standards).
The HD6000 series is becoming quite weird... It now has some three different architectures (if you include the HD6870 as 'different'), each with a different set of features.