If you get 4x the clarity, then you can reduce the size of various things, font ...

snikch on June 12, 2012 | parent | context | favorite | on: The New Retina Display MacBook Pro: A downgrade fr...

If you get 4x the clarity, then you can reduce the size of various things, font size, window size etc. So while the concept of resolution as you know it may not have changed, you can easily put more 'stuff' on the screen – more real estate.