Do you have a link on a Titan modded to 1200MHz?
With the BIOS mod it's not that uncommmon. One of mine will do more than 1200, 1220 or so, the other does 1180 something.
When you clock them that high it's about a 20% improvement over the standard boost clock. I didn't spend much time playing with only a single card, but I did play some Battlefield 3 multiplayer for a while using only one. I couldn't tell the difference between the single overclocked Titan and my previous 680SLI which I ran at 1200. It's really fast once you clock that high.
It seems there are only about 2 people in this thread who realize all these rumours are stemming from an article on 3D center hypothesising possible upcoming cards and what they may perform like. I don't think nvidia has any interest in getting away from selling 300mm2 dies for $500 and 500mm2 dies for $1000. I bet we see a Titan Ultra for a $1000 around Christmas time and before then 780/770/760 with a refined GK104 and a Titan LE for $650-$700.
It's also my impression that Titan and K20X are essentially using exactly the same cores with a few pro specific features disabled on Titan, but the functional SMX & core counts etc are identical. I don't know that Titans are cast-off K20Xs, so much as they are just the same GK110 cores being used for the geforce lineup. This is no different than what happened in the past as well, apart from the massive price increase this time out on 28nm.