5.5-inch iPhone 6: @3x

John Gruber:

The bigger battery also explains, partially, why I project that the 5.5-inch, and only the 5.5-inch, iPhone will get a super-high resolution screen (461 PPI, I’m guessing, give or take a pixel or two per inch) and will run at @3x retina resolution. More pixels consume more power.

Gruber expects the 5.5-inch iPhone 6 to sport a pixel format of 2208×1242 and @3x, which means “‘triple’ retina resolution”.