Simply wait ;-) probably with age your sight will decrease and at one point you simply will stop to see difference. I guess that 70% or more of people in theirs 30's will have problem with seeing difference (except brighter colors). Of course in one or two years everything will have screens with more pixels, but from some point it will be always only marketing thing.

As for now if you look on 22 cm long screen with resolution 1280 pixels for width, and you keep screen in 0.5 m distance it means that one pixel have size of 1.17 minute, so some, and maybe even most of people aren't able to distinguish single pixels.

Some people are using tablets for work, some are doing the same on phones, but for many computers are much more comfortable. It is very personal thing, for me tablet is cool for playing in some addictive games like Cut the Rope or Where's my water? but I will kill anybody who will propose to change my computer which I'm using for development for any tablet. The same, after reading several books on tablet I much more like reading on Kindle, it hasn't this ugly glossy screen when I can see me instead of text ;-)