Its official, launch date of AMD’s next generation high-performance Radeon HD 7000 series GPUs is 9th January. DonanimHaber posted a picture of an invitation card to the official AMD event where two graphics cards based on 28nm Tahiti architecture will be launched. These cards are HD 7970 and HD 7950, most likely.
Source also has a pciture of invitation card to the vent but that's not in English.