So, because of some really weird budgeting constraints I can drop $1100-$1200 on video cards. I've just got a pair of shiny new Dell U2413 monitors - they run at 1920x1200 and ran me just under $1000. This will likely never happen again while I am in school.

My primary use for the cards is going to be computational, not gaming. I'll be using them in CAD, 3D rendering/ray tracing (CUDA based in Blender 3D), Matlab, and other things that would generally warrant a Quadro card. However secondarily they will be gaming cards therefore it would be lunacy to spend the money on Quadros. I game in windowed mode, therefore I am not considering AMD cards despite recent advances in Blender 2.70/2.71 that let them render in OpenCL (Hi Googlers! Try it. It works! An R9 290 will take twice as long as a GTX 480 or about 4 times as long as a GTX 780 non-TI!) I'm certain that they will improve performance, but if Crossfire won't work in windowed mode, I see no reason to buy in to it! Plus I'd want my R9290x cards to be water cooled.

My primary constraint is RAM. For 3D rendering, the RAM is a hard limit on the complexity of the scene I can render. I've seen rumors that the GTX 880 card is going to have 8 gig cards floating around, which is a 33% increase in my potential scene complexity for my 3D modeling projects.

They're supposedly just around the corner. The money isn't going to vanish very quickly. I can likely hold on to it for a few months. So: Do I want to go for the pair of GTX 780 6 GB edition cards, or do I want to try to wait for a pair of GTX 880 8 GB edition cards with the hope that the 880s will be less than $1200 and launch before December?