Besides the relative disappointment that was Google Talk's lack of a Mac version (which has been blogged about to death and I won't go into anymore), I've been waiting for a native version of Google Earth for what seems like ages now.
Objectively, it's been only a month and a half, (which isn't enough for anyone to port anything of substance to Mac OS X and do an adequately polished job), but I must confess it's getting to be somewhat annoying, since the Google Maps API isn't flexible enough for what I've been doing with GPS data.
Besides not wanting to publish on the web most of the data I'm dealing with (and having spent quite some time figuring out how to generate areas and overlays in KML from it), it's a pain to run Windows inside emulators, Remote Desktop (yes, Google Earth can be run via RDP) and whatnot, even if the graphical bits are relatively speedy.
Under The Hood
Keyhole has been around for a while, and Earth is an OpenGL application, so it shouldn't be rocket science.
In fact, it only took a cursory peek into Program Files\Google\Google Earth to confirm that the UI is based on Qt 3.3.4, and there are definitely DLLs for libcurl, expat and xerces in there (plus, for some reason, mention of an AdSense module in the xml folder).
Which means Google Earth uses a lot of cross-platform libraries that have already been ported time and again (some of which are even included in Mac OS X) and makes it look like it can, barring major issues in the proprietary bits (which, let's face it, are most unlikely), be ported to every variety of UNIX under the sun (yes, including the omnipresent penguin).
So, what's holding them back? Testing? Summer? Qt (or whatever) licensing? Making sure they get it right?
Or, like Scott Rosenberg put forth, because most of the eyeballs are on Windows?
The world doesn't stop where the "Start" menu ends.
Yep, and there's life beyond the blue screen.