High DPI displays are coming fast, will it scale well on Linux?

With new Haswell ultrabooks just around the corner I really have my doubts how good GUI scaling will work on GNOME / KDE / Everyone else.
Acer Aspire S7 has a 2560×1440 panel, Fujitsu Lifebook UH 90/L sports A MASSIVE 3200×1800 panel.
The new ultrabooks are starting to look very nice, but it won’t help if your favorite app looks like bad.

I’m kind of a sucker for a Macbook Air 13 with 12 hour battery life, even if it only has a 1440×900 panel.

Here is a nice picture of a Macbook Pro Retina running Ubuntu.