I've been having a thought creep up a lot lately, and that is some sort of display with built-in anti-aliasing. Would this be possible or plausible?
This is pretty much the purpose of 2560x1440 and 2560x1600 resolution displays. The purpose of using AA is to rid of the jaggies created from the pixel density of your display, which is why a lack of AA at 720p is much more noticible than at 1080p. Using ultra high res displays almost entirely rids any need of using AA, as the pixels are so dense that the jaggies disappear almost entirely.
Don't forget 4k!
But, yes, having high resolution eliminates the need for a high-AA, or even any at all, but takes just as much, or more GPU power to drive those pixels, so it ends up cancelling out.