Man of Honour
It all depends if Nvidia are going to drop another Titan.
If they don't then you know the performance mark AMD will aim at. The 970 and 980, low bar. The fact nothing has been mentioned from them probably indicates they have something to counter big Maxwell.
If that's the case, it's anyones guess.
For AMD the 970 and 980 are not much of a challenge as the 290Xs are already slightly faster @2160p.