At 2560x1440 or 2560x1600, players will require 2-Way SLI GTX TITANs, 3-Way SLI GTX 670s, 3-Way SLI GTX 680s, or Quad SLI GTX 690s to enable 2X SSAA, resulting in an effective resolution of 3584x2016 at x1440, and 3584x2240 at x1600. On the Quad GTX 690s, higher levels of SSAA should also be possible.
So far all has run perfect for me with 2xAA on 670 Sli. Reading this I expect some slowdown later on.