VR Zone found some leaked benchmarks of AMD's Radeon HD 6850 and Radeon HD 6870, you can check it out over here.
It includes results for DiRT 2 and BattleForge.
The two cards are titled "1120" and "960", referring to the SP count of the two variants, HD 6870 and HD 6850 respectively. The first benchmark is Dirt 2, Ultra DX11 at 1920x1200, 8xAA, 16xAF. The HD 6850 ends up 33% than the GTX 460 768 MB and a good 10% faster than even the GTX 460 1 GB. The HD 6870 is just as impressive, being 20% faster than the GTX 460 1 GB. However, it fails to open much of a gap to the HD 6850, being less than 10% ahead. Considering the GTX 460 1 GB's previous strong showings in the Dirt 2 benchmarks, on par with the HD 5850, these are some impressive numbers from the Radeon HD 6800 series cards.