Possibly some of these could be part of the paid service, but…
Google Earth needs better flying controls. They should separate viewpoint attitude and viewpoint direction.
In addition, IWBN if Google would:
Scale a distance indicator and put it in perspective on the ground. Do the same with the compass.
Show country names on either side of visible parts of borders.
Hook up as many 3D buildings as possible to the drawings on SkyscraperPage.
Import, map, and update weather information: temps, clouds, winds, rain, etc. Make the clouds available in 3D.
Add ocean currents!
Allow export of movies of zooms through the landscape. There should be an option to slow the export of movie frames down until all the objects in each frame are rendered.
Fix the poles. I’m not sure what’s going on there, but the South Pole looks very… odd.
Hook the system up to land registries as another data layer. Click on a tract of land, see the borders, find out who owns it.
Add pilots’ information (both sea and air).
Clarify copyright status and licensing of the images. I’m working with someone who is very interested in using Google Earth images in travel videos.
Provide a phone number for licensing and sales.
And make Sugarloaf Mountain 3D, dammit!