There seem to be a lot of "doomsayers" thinking that here's a 100% chance that AMD is dead in the water. This thread has been useful for one thing - figuring out who has a solid grasp of reality and who does not. I will keep it in mind in the future when I browse these forums. Let us consider the situation.
The GTX 980 is approximately 5% faster than the 780Ti and perhaps 10-12% faster than the 290X. That is not a huge performance gain. It has however gained perhaps ~40% in terms of power efficiency, which considering this is still the same process is a notable achievement. The higher the resolution, generally the more AMD closes the gap. I suppose that could translate into more overclocking headroom.
All in all, I would estimate that Maxwell has about a 60% lead in performance per watt in gaming (but not in compute) compared to the 290X. The 970, like the 290 compared to the 290X is by far a better value, although retailers have begun marking the prices upwards. Whether the price will go down in the future remains to be seen.
Scaling in 970/980 SLI does not appear to be as good as the 290/290X in Crossfire. You get about 65-70%, averaged across most games, compared to ~80% with CF. I wish that Nvidia would adopt a solution like AMD through PCI-E lanes. This is actually not a huge lead if you think about it.
The situation is certainly not as bad as say, the 8800 GTX vs the 2900XT. We have yet to see what AMD has to offer at this point. I will not judge until they release something. AMD has managed to make some impressive feats in the past, most notably their 4870 and 5870 cards.
The other interesting thing is whether or not a "large" Maxwell is coming >550mm^2. Very likely so. Personally that's what I plan to do - wait and see what AMD releases and see how it stands up against a big Maxwell. The 28nm process is quite mature, so we should be seeing a big die in the coming months - hopefully with shader, seeing that it is a mature process.
As far as the fans of either side - well very simply put, what the other side releases is not really important to you. You are never going to buy it anyways. It's only use is that it will lower prices for your side if it offers competitive performance. Remember - neither company is your friend, they just want your money.