Simon Chapman starts delving into Google Earth’s C++ codebase and comes up with a basic COM interface.
Slightly tangential thought: I wonder if the Mac version will be scriptable? Using Automator/Applescript to take timelapse video of weathermap overlays would be a bit of a trip. Or we could try to scrape geodata from the frontmost web page in Safari and have Google Earth fly there while we surf. In other words, there is room for a Google Earth equivalent of the Google Maps API.