I havent seen any talk on this list about it's release so I thought I'd pop it in:

http://googleblog.blogspot.com/2006/01/google-earth-in-mac-world-pc-too.html

Those of you running tiger will have to let me know what its like :-(

Google earth runs okay on Tiger.
I am not sure of all the features and havn't seen it on a PC.
The terrain and building option works
so I've been and had a look at the Himalayas ( to see the terrain) , Chicago, New York (to see the buildings) and Hopetoun - (to see if one of my buildings is shown it was but a poor resolution)

So I guess the maps of google earth are of similar resolution as Google maps, so for much of WA are nothing flash. however the terrain relief in the detail resolutions are great.

Get yourself a copy.
--
Gary Dorn
Permaculture Architect
Perth,  Australia