I think it's not compatible with the 70 because it wouldn't benefit from it. I think this time around the x80 will truly be a sizable margin faster than the x70. My prediction.
Actually, I think it's just marketing, and they're trying to put the 1080 in the spotlight. I'm guessing it's going to be compatible with the entire 10 series
Neither am I, honestly. I hope there will be plain boring black ones that don't stick out.