Hitachi has announced a 4.5 inch screen for mobile devices that fits 1280x720 pixels in its frame. Thus there are 329 dots per inch. The iPhone 4 has 326 dpi. Plus, it will have a 1,100:1 contrast ratio. On a phone? Awesome!
I completely agree when Engadget says "That basically means CES 2012 is going to be filthy with handsets offering full 720p resolution -- we can't wait."
[Hitachi via MobileCrunch via Engadget]