The world was quite happy with iPhone 3G/3GS screen until they saw iPhone 4 screen. Same thing is happening with MacBook Retina vs the older generation MacBooks (whose screen I did not like for lack of resolution).
I have 1920x1200 pixels on my 15" thinkpad. This was the highest resolution display before Macbook Retina came along, and I noticed the difference between my screen and other displays of the time.
The production cost has little to do with number of pixels, it has much more to do with economy of scale. Eizo is certainly not in a position to have that kind of economy, even NEC is not there. Only Apple, Sony, Samsung, and the likes have the muscle to pull this off. I am sure Apple retina laptops have set the wheels in motion for other makers to offer something similar (for one thing, the factories building displays for Apple already have the production processes in place). So, hopefully in a year or two we will see better densities on LCD monitors.