Thanks for all the feedback after my initial release of Thematic Mapping Engine. Two features have been requested; data upload/import and support for the new Google Earth plugin. I've now added a Preview-button, which enables you to see thematic maps in the browser instead of switching between two applications.
The Google Earth plugin seems to render big and complex KML files very well. The image above shows GDP per capita in 2005.
A missing feature is support for KML time primitives. The TimeSpan and TimeStamp elements are not supported, and the plugin renders all the polygon features regardless of the time specified (above image). This will hopefully be fixed in a future release.
By the way, Thematic Mapping Engine still works without the Google Earth plugin - just click the Download-button.