Gruber ignores the Droid, which has sold far more units than the N1, does not have the Pentile subpixel reduction, and has an 854x480 display. A 960x640 display would rock but given that the LCD is smaller than current iPhones, I think it will be a 1.5x increase which will look fine with antialiasing and font/UI element scaling. So 480x720.