Follow my math rant and you will see why this makes very little financial sense for a manufacturer.
Currently the smallest 2560x1920 display is 27", with 310.2 square inches of surface(23.5x13.2), 4,915,200 pixels and a pixel density of 125 ppi2.
The new proposed 17" laptop screen will have 103.6 square inches of surface (13.6x7.6), 5,184,000 pixels and a pixel density of 193 ppi2.
The iphone 4(s) has a 3.7" screen with 5.76 square inches off surface(3.2x1.8), 460,800 pixels and a pixel density of 283 ppi2.
I'm not saying this isn't possible, just that to get a 66% shrink in surface area (310 to 103) with a higher amount of total pixels you better expect really really poor yields for the first 6 months to a year. The only reason why phones have really high PPI screen's is because they are small, so if there is a dead spot of pixels they loose one 5.76 square inches, not 100+ square inches. Because of this the cost of a single dead pixel in a screen of this size is 20X more costly than a dead pixel in a 3.7" screen. If apple intends to sell these expect supply to be extremely limited and price to be extremely high.