is the case with almost every AMD AIB partner, Asus has also rolled out its own Cayman based HD 6950 and HD 6970 cards. The interesting fact is that Asus is the only partner that has decided to go for a factory overclock, at least for now.
Both the HD 6950 and the HD 6970 are overclocked by 10MHz, which is probably something that you can do by yourself, but bear in mind that Asus does this but keeps your warranty. This means that the HD 6970 ended up clocked at 890MHz for the GPU while the HD 6950 works at 810MHz for the GPU.
Unfortunately, the factory overclock isn't extended to the memory so you are looking at cards that have 2GB of memory clocked at 5.5Gbps for the HD 6970 and 5.0Gbps for the HD 6950. Both cards also feature Asus' Voltage Tweak feature and full aluminum fan shroud/cover that should help in heat dissipation.
You can find them here