If you're insanely rich, why not. If you're just rich then get e6600. Like lance said, it can OC to 6800 speeds easily. And then use the other half of the money you were gonna spend on the X6800 on more essential parts.
3770K | ASUS STRIX GTX 1080 | DDR3-1600 16GB | CORSAIR 650D | CORSAIR HX 850W | CORSAIR H100 | SOUND BLASTER Z | ASROCK EXTREME4 GEN3