Unlikely this will happen, unless mobile OS take over the desktop: desktop OS still blow at density independence, and so do their GUI toolkit.
Highest density desktop screens you can find are still IBM's T220 and T221 (from back in 2001) with 204DPI in 22.2" screens (3840x2400 native resolution)
They're getting there. Cairo is fairly neat these days, you can actually take vector screenshots of applications.
That's like saying your language has perfect unicode support because its strings are encoded in utf-*. It's part of the requirements, but a very long way from solving the problem.
All of my icons are SVG and my applications are rendered in vectors. Seems like a pretty damn good start.