It depends, some of the Windows laptops with smaller, but high resolution displays are between 126 and 160dpi. The 27" display is also in the high 120s.
IBM released a 20" display back in the 90s with well over 200dpi, but it never took off...
I don't know how useful such a high density will be, more space is important to me, as opposed to more definition for individual fonts etc. I hate the current trend of castrating 24" monitors, so that they lose the last 180 lines, just so they can have the FullHD logo. I want a computer monitor, not a despecced television!
I think this is more likely, in the short term at least.