As you probably already read on various other hardware tech sites, Nvidia is planning to release yet-another Kepler based graphics card in the summer. As TechPowerup writes: "... The new SKU could feature 13 out of 15 streaming multiprocessors on the GK110 silicon, working out to 2,496 CUDA cores, 208 texture memory units, a 320-bit wide GDDR5 memory interface holding 5 GB of memory, and 40 ROPs ..."
As Nvidia quite simply disallows any customisation of the PCB, there will be no Lightning, Classified or Matrix available. As far as the rumours go, the new card might very well be released as GTX 685 or perhaps even the GTX 780. As the Titan remains top-range with 2688 CUDA cores, the new in-between SKU would come close in terms of stock performance with the rumoured 2496 CUDA cores and still be significantly faster than the GTX 680, which only has 1536 CUDA cores. The new card will see custom versions - just like the GTX 680 - and therefore might be more interesting for overclockers than the GTX Titan.
For those who hope the GTX685/780 will be to GTX Titan what the GTX 275 was to the GTX 280, don't get your hopes up. Although the GTX 275 clocked a lot better than the GTX 280, 1400MHz versus 1100MHz, this large difference in overclocking capability has not been repeated on either the GTX 400 series or even the GTX 600 series. After all, the GTX Titan clocks roughly the same as the GTX 680.