In my opinion, this card and the Titan is actually a clever product release by Nvidia. Much like the GTX 680 and GTX 670, the Titan was released at higher price (like the GTX 680) while the slightly slower GTX 780 (the GTX670 for the GTX600 series case) is at a significantly lower price but performing quite close to it's higher-end brother. We all remember when the GTX 670 launched it makes the GTX680 looks bad because the GTX 670 was 80% of the price while maintaining around 90-95% of the performance.
Of course, one could argue that as we get closer to higher-end products, the performance increase is always minimal and price to performance ratio starts to increase, however, for the past 3-4 years (or so I guess), never has it been that the 2nd highest-end GPU having such low performance difference with the highest-end GPU. It's usually significant enough that the highest end GPU (GTX x80) still has it's place.
Tl;dr,
The GTX Titan was released to make the GTX 780 look incredibly good, and people (especially on the internet), will spread the news fast enough claiming the $650 release price for the GTX 780 is good and reasonable, and people who didn't even bother reading reviews and benchmarks, will take their word and pay the premium for GTX 780.
Nvidia is taking a different route to compete with AMD or one could say that they're not even trying to compete with AMD in terms of price/performance (at least for the high-end products).