3840x2160 resolution on a 15.6" screen which is Chroma Tune calibrated and Technicolor Certified.
Toshiba are going to be the first with a 4K notebook release next week.
Its going to be be powered by an AMD Radeon R9 M265X
Lenovo should follow shortly with a Y50 model and a 4k screen
Wonder how Windows will scale to 4k, I have enough issues with 1920x1200