My 2 cents:
Judging from the performance reviews of the Titan Black and the 290X, the Titan Z should best the 295X2 by the same small margin. However at my preferred resolution of 5760x1080 the Titan Black only bests the 290X by 1 or 2 frames in most instances so it's real hard to justify the additional $500 in price.
This price difference will only grow exponentially more ridiculous with the Titan Z slated to sell at twice the price of AMD's $1,500 295X2.
So yes Nvidia’s $3,000 Titan Z graphics card will most likely be king of the hill, but at what cost when a card at half the price is almost as good, and two 295X2 at the same price will completely blow it out of the water!
IMO the Titan Z will be a great card at an idiotic price. As far as one card being a pro card and the other being a gaming card, that is complete rubbish! Both of these cards are gamers that can be used successfully in many professional applications as well. If either of these cards were pro cards they would be called Quadro's or FirePro's