OK, after careful consideration, I've made my decision.
I'm going to keep them. This is why.
First off, these were the other options I was entertaining in my twisted mind:
1) Send the cards back, get a pair of GTX 760s
2) Send the cards back, get a single GTX 780 for now and buy another one when the price drops
The 760s were definitely an attractive offer, especially if you're money conscious. However, as I've said repeatedly, this "remorse" was never about too much money being spent. It was about value for my dollar, which is different.
The 760s would easily have lasted me until next year I wager when Maxwell came out, and it would cost me only a 100 bucks since I sold my GTX 580s for 435. But when I considered it, I decided not to do it because I made a vow a few years ago to never again buy a first generation card after getting burnt from buying two GTX 480s, only to have NVidia release the GTX 580s a few months later which were better in practically every way.. So I will only buy the respins or tweaked cards.. Basically, I would have ended up holding on to the 760s longer than I was willing to do since NVidia will likely release the Maxwell respin in 2015..
Now for the next option.
Sending back the 770s, and getting a single GTX 780 in it's place and overclocking it as high as I can get it to hold me over until AMD releases their next gen cards, or NVidia releases Maxwell which will force a price drop on the 780s, enabling me to buy another one.
I decided not to do this for one simple reason. I don't want to be an "enabler" for NVidia to think it's OK to charge 650 dollars for their flagship GPUs. I've always bought NVidia's highest end GPUs, as they typically cost 500 bucks at launch, which I think is reasonable. However, 650 dollars is to me, unreasonable and I don't want to be party to it.
Can I afford two GTX 780s? Yes I can. Heck, if I was willing to drop 900 bucks on two 770 4GB cards, what's another 400? But the point is, NVidia will now use the successful sales as a precedent to justify hiking up prices even more in the future.....and who can blame them really? They are a business, and if people are willing to pay, then let them pay.. I can't control what other people do with their money, but I sure as hell can control what I do with mine..
Also, I don't think the GTX 780 is "worth" 650 bucks. It's overpriced, much like the Titan, though not nearly as bad. If NVidia had it going for 550 instead of 650, then maybe.....just maybe.
So that leaves the GTX 770 4GB. I think this is the best bang for the buck high end solution out there right now. It's the only card to my knowledge that can reliably approach the GTX 780 (overclocked of course), while costing significantly less. It also has an extra 1GB of high speed VRAM, which will certainly come in handy both now and in the future. While games today may not use all of that VRAM for rendering, many still use it for preloading textures and other game assets.
So basically, I will keep the 770 4GB and probably miss the first iteration of Maxwell and get the respin if I think it's worth it.. Despite what RussianSensation says, these cards will be good for a long time. The next gen consoles will enable higher graphical fidelity games than what we see now, but not radically so. I don't care how close to the metal they can go for optimization, but there is no way in hell they are going to overcome the massive deficit in raw power between the APUs in the consoles and the hardware in a high end PC.