People this is basic economics and marketing at its most extreme. First off, AMD's monster R9's were tested and released with the shoddy cooler so that after market vendors would get a big chunk of the action. For example the card heats up like a freaking toaster then what do we do? We buy after market cooling, AMD already made a profit on the reference design and they will continue to sell those amazing gpu's (for those who actually saw the performance without throttling like Toms hardware review of the R9 290+Accelero extreme III) no matter what. Now After market vendors (Sapphire, Msi, Asus, XFX etc...) will release their own version with better cooling so they will also sell lots of them and on and on ad infinitum.
Nvidia just unlocked the full potential of Kepler and in essence crippled Titan halfway. I don't think a 780ti 6GB version is coming because there is that small "insignificant" thing that makes people buy Titans and water blocks, because they want those 6GB of ram. While those of us who want to get ahead and don't have the means end up with 780's with elpida memory which is what's gonna happen when people start receiving their retail versions of the 780ti. Reviewers and the media get those Hynix, Samsung memory equipped, golden sample Gpu toting samples and we get the ones with mediocre asic GPU's and elpida memory. They won' t get to where most review samples get and we'll end up with basically the same GTX 780 with a bump in the core clock. And after a few weeks the after market crew comes in with Winforce 3, Lightning, Classified, Direc Cu II-III etc...) and it will sell again. People I urge you to pick the card of your choice and stick by it, you paid for it enjoy it; go play.
In the end to actually enjoy gaming (and no 4K, its still too immature) I don't think anyone needs more than a single GTX 770 or a 7970 (aka R9 280x) but if you need more then fine just aim for whats more convenient for you because I have seen to many weird variations on the reviews I've read the past few weeks and I've tested myself with my own Nvidia and AMD Gpu's to know that something fishy is going on. The monster 780 Ti is maybe 700 3dmarks (Firestrike non extreme) away from my overclocked GTX 780 Classified and yet in games the Ti even overclocked doesn't overtake me more that a couple of frames (from 2-5) so I have no reason just like most of you to upgrade, its just hype wait for it and the best products will be available soon, those reference cards won't be kings much longer. Anyway I repeat; go play and let the companies sort themselves, after awhile coma back and buy whichever pleases you the most.