My 15" MBP has the 1680x1050 anti-glare screen, which really pushes the usability of some of the OS X widgets. Any 15" MBP can be ordered with it. I don't know if you'd want to go that much higher on any "modern" OS, until they are display resolution independent.

Too small of a dot pitch simply makes most operating systems unusable or irritating -- this box is too small, this text in this section needs to be enlarged, this document needs to be zoomed -- and so the demand for higher resolution displays just isn't there.