The GeForce Titan reportedly has 2688 CUDA cores, a 384-bit GDDR5 memory bus, 6GB GDDR5 memory and a 235W TDP.
Incidentally, the current fastest supercomputer in the world bears that name (Cray Titan, located at Oak Ridge National Laboratory). Even as the GK110 silicon physically packs 15 SMX units, totaling 2,880 CUDA cores, the top GeForce Titan variant is said to use not more than 14, amounting to 2,688. This is probably to help maximize yields of the GK110 silicon. The chip features a 384-bit wide GDDR5 memory interface, 6 GB will be the standard memory amount. The target TDP of the SKU is set around 235W.