PC Perspective posted their AMD Radeon HD 4850 512MB Preview
A quote from the article:
>> AMD Radeon HD 4850 512MB Preview - RV770 Discovered
AMD got caught with its hand in its own cookie jar - HD 4850s have already hit the street for sale so we are able to bring you a quick preview of the RV770 before its official launch date next week.
>> AMD Radeon HD 4850 512MB Preview - RV770 Discovered