I think that at 1080p and 1440 the 290X will be within a few frames up or down compared to Titan largely depending on the game selection. More or less a tie. This means the 780 will be anywhere between 8 and 15% below. In order to reclaim the top spot, debatable because it will depend on so many factors, Nvidia needs to put out a 780Ti which is faster than Titan with at least 5%. Question is, are those specs enough? A 780 running slightly above 1Ghz is a Titan. 2496 sp running at 1Ghz might bring those percentages needed into play. But it's an insane game of getting just a few frames more. Maybe this GPUz is fake and we are talking BS.
Technically speaking, Titan still retains the single GPU crown based on leaks - so if that performance is brought down to a reasonable price at stock clocks and reference cooling, then the single GPU crown just got more reasonable in price. The entire problem with Titan is not "single GPU crown". The problem is price, I really think that's what NV is fighting with respect to the 290X. Let's say the 290X trades with Titan and costs 600$. That would make the Titan look really stupid (moreso than aftermarket 780s already do), but if they bring that performance down to 650$, all is well again.
I think last I saw the Titan was winning 60% of benchmarks based on leaks, enough to retain the crown. So I think the strategy is to bring that level of performance to a GTX 780 price. The best part is if the 780 lowers in price by 50 bucks or so, that would put tons of aftermarket 780s in the 600$ or so range. That could put the 290X in a tough spot and make it a tough choice for GPU purchasers, it would look like this, theoretically:
290X, 600$, trades with Titan, free BF4
Overclocked aftermarket GTX 780, 610$-620$, same performance as 290X, 3 free games
Reference GTX 780, 600$, 10% less than 290X at 1080p, 3 free games
So my main question is what price will the vanilla 780 be after all is said and done..