The frame time's really an issue for SLI and Crossfire configurations. It wasn't unusual, in 2-way high performance configurations, to get into a situation where the frame time of half your frames was zero. And while this shows a very nice frame rate, it doesn't mean you see that frame rate -- because frames with a dwell time of zero don't actually show up on your screen!Yeah I agree with eskimoe, the 780 will handle this game awesomely at 1080p.
I wasn't really worried about running the game at 1440p until Guy N'wah made that post about frame time when comparing resolutions, I jut hope the game is not super difficult to max out.
nVidia and AMD both have frame pacing in their drivers now, and this means it should usually not be a problem. But it still means frame times, and the distribution of frame times, need to be measured when you're evaluating and tuning a high-performance configuration. MSI Afterburner does a good job of it.