hi ppi IS useful. you don't need antialiasing software and such crap if you have hi ppi. personally, I would be able to find use for a wqxga (2560x1600) in a 14" or 15" laptop screen. And no, font size does not become tiny if one does not want this to be (although I want tiny fonts), with the new desktop technologies like microsoft aero or linux counterparts like plasma and compiz.
http://en.wikipedia.org/wiki/WUXGA
why we are going backwards: http://www.nytimes.com/2008/11/13/technology/13iht-13panel.1...