OK, the new macbook pro and retina display is damn cool.
In fact, it suffers from being too good!
This is a problem that I had previously encountered on a nice IBM screen (3840x2400). The pixels were too small for most normal desktop operations. Whilst it is often possible to increase font sizes, you can rarely increase all of the icons and window decoration on many systems in quite the same way.
Now apple have been clever - you get to select a virtual desktop resolution, e.g. 1920x1200, and it then scales to the actual screen resolutions of 2880x1800. This may sound batshit insane, but in fact it makes more sense than it sounds. The clever bit is that the scaling really only applies to things like bit maps (images) as the fonts are rendered using the native resolution anyway. So the virtual desktop is really just a major scaling factor not a loss of resolution. All very sensible.
Except... One assumes that the clever logic to use the native resolution where you can (fonts, and presumably vector graphics, etc), is only possible if you use the right libraries. Some non-apple apps don't.
This is a slight nuisance for me, as I normally use Firefox and Thunderbird for web and email on all of my machines (my desktop machines are linux of various styles). These apps do work, but they work as if the screen was the virtual desktop resolution, including all fonts.
Fortunately using Safari and Apple Mail is OK. Their mail app is actually pretty good. So I have gone the apple way rather than the fuzzy way. Still can't see where I set default fonts on Safari though.
There is no screen option for native 2880x1800, but there is some good news - apps like World of Warcraft simply see all the screen options including a native 2880x1800 and work really nicely - cool. No oversampling is offered, but to be honest, with pixels this small, you don't need it.
See.. Right is Firefox, left is Safari :-