I'm in the same boat with the second GPU...I know I'm going to need it, it's only a matter of time. Trying to hold off the massive temptation Brahmzy and the others are providing for swapping the 6700 for a 7500 because of the $450 I can then put towards another Titan lol...
Another Titan X? I'm still waiting on purchasing my first one. I have 3 (original) Titans. No way am I going to spend 3k on GPUs again. I'm waiting on the 390x or 980ti before I upgrade.