I wonder, if I will buy one... I think I have 50w left on my psu...
However, I am still undecided because of its performance outside those specific new algos (I have the feeling, it wouldn't bring much more on top of what the 290x and the 780ti are already bringing...)
That's exactly my line of thought. I would buy 4 new Maxwell cards today IF they had an improvement on the hash rate of a 780ti. Their latest double Titan is slower than just buying two (overpriced) titans. If NVidia waits much longer the net hashrate of altcoins will make new offerings less attractive. I would buy big Maxwell cards today if they had 'em, but I might buy nothing if they wait two more months to release.
I might have paid $700+ each for 800 series cards back in March, assuming they match a 780Ti in performance, but I wouldn't even pay $300 on one now unless it doubles the 780Ti performance (I'm not holding my breath). I can't believe people are still dropping $400 for an AMD R9 290. I guess demand has returned to the domain of gamers and CG artists.