My computer is completely stacked for D3, except for the video card. I have a GTX 470 that can run D3 at max settings and SC2 at max settings simultaneously while maintaining 60 FPS. The issue, however, is that even when running only diablo the card gets upwards of 70c and I have to have the fan at 80% to keep it at 70c.
The fan is SOOOO LOUD, seriously, it can be heard across the house. I know it's more of a luxury, but do you think it's worth it to upgrade to the 680 for the quietness?
The old Fermi 470/480 are known for high temps and laudness.
It all depends how much you value quietness. If you now upgrade to GTX680 you will have it for years (since new consoles won't come out at least until 4th quarter 2013). If you have the money I would say, yes. But for sake of any gods you belive, never buy referent cards. Ever. Go with Gigabyte/Asus/MSI etc., at least those 3 have always far superior cooling systems then standard NVidia (or AMD) version. Unless you want to just go WC.
The problem is that, right now all manufacturers use standard cooling on GTX680. For example, Gigabyte hasn't made 680 with their Windforce 3 colling system yet. You can always switch to 580 if you want to switch it as soon as possible, it will be more then enough for years also, and later on you can buy second one for SLI.
Your case would have to be like bunker to silence 470, especialy if it's referent. Of course, good case can help (like my Fractal Design R3), but the problem is that GTX470 is just too loud.
My PC is on my desk, like 30cm away from me and I can't hear my Gigabyte GTX460. Unless I play THe Witcher 2, then my card get's a bit loud, but still, I can't hear it from like 3meters away.