The good kind of insane, mind you. With full 1920x1080 resolution and a pixel-per-inch density of 440, it kicks the backside of any phone display currently on sale.
Which isn't to say that LG's display is on sale just yet; Pocket-Lint reports that the display will actually start shipping in the second half of 2012. It's an advanced High Performance In-Plane Switching (AH-IPS) panel, and while it'd be tempting for LG to keep it only for its own smartphones -- especially as it recently admitted it had "dropped the ball" on smartphones in recent history -- something tells me this might just be a highly sought after OEM product instead.
There is naturally enough the issue that 1080p on a 5-inch screen is overkill; at the kind of distance you won't possibly be able to make out the resolution differences clearly. It's a glorious, insane kind of overkill, however. Isn't that the best kind? [Pocket-Lint]