What are you talking about? An overclocked GTX 780 will easily match that as an overclocked 780 is faster than a Titan and was the Titan killer before AMD used the slogan to pump up the 290X.
Well, if the goal posts shift to overclocking then AMD has already done a hell of a job. Keep in mind that the Titan overclocks very well, too, and once you use the skynet BIOS you can easily match or exceed clockspeeds that GTX 780 users are using. There are modded Titan BIOS users over at OCN who have overclocked in the 1250mhz+ range, which is generally where the best OC'ing 780s are. The issue with the Titan is that the stock BIOS is very restrictive on TDP limits, and this is why the skynet BIOS completely eliminates that issue and "opens up" the Titan, so to speak, with respect to overclocks.
All cards can be OC'ed. Xtremesystems has more or less stated that the 290X overclocks very well on air. Therefore it stands to reason if AMD releases a 290X at a sub 575$ price level which trade blows with the Titan at stock, then the same would be equally true once everything is overclocked. I'd also imagine that AMD doesn't have the TDP / thermal limits that GPU Boost 2.0 does, although you can get around that with a modified BIOS on the Titan.
Again - if the goalposts shift towards overclocking, AMD has already done their job assuming the price is right. For the past generation everything has overclocked equally well with most cards gaining an average of 10-13% of headroom with even a modest overclock. I'm sure the same will be true of the 290X - so you can say "wait the 780 overclocks!" - well, i'm sure the 290X does as well. Various websites are hinting at great air OC's with the 290X, as well. So I guess the response is, "so what if it does overclock?". I would imagine if the 780 gains 10-13% with overclocking, that the 290X would too. So then the response, again, is "so what if the 780 overclocks".
These are generalized speculations, but i'd expect everything to OC just fine based on what I've read at chiphell and other places (that have directly tested OC'ing on the 290X) I'm anxious to see real data as everyone else is, and the situation with the NDA is very annoying to say the least. That said, I personally find the prospect of a 550-575$ 290X very exciting - at that price range, I would imagine that NV would need to shift their pricing downwards on both the 770 and 780. And who wouldn't be happy about that, seriously? Everyone wins if AMD pulls this off, even nvidia users.