As far as my research has gone(a fair amount), I know it'll be the newer and better architecture: 28nm. Cooling, temperatures, TDP, etc. is supposed to be phenomenal. Um, NVIDIA is delaying it to Q1-Q2 of 2012, while AMD is releasing their 7000 series with the same architecture by Q3-Q4 of this year(probably November, December-ish) Tri-sli-ing GTX 580's sounds great, but if you're patient, I'm sure you could go and tri-sli GTX 680's next year, with less worry about heat, noise, and not have pet peeves about something like you not having PCI E. 3.0 cards.. um the latest DX or OpenGL... things like that. x]. My final thoughts: Wait. You know what they say... "Good things come to those who wait."(especially when it comes to the tech world)
. But that's just my opinion. Hope I helped!