I should have written this earlier, NASA WorldWind server (http://wms.jpl.nasa.gov) was down for some time, and still is. So gaia currently only displays cached data or just gray square.
Cleaned up source code of gaia was just checked into SVN. Google Earth support is gone, but NASA World Wind support was added and it works.
First release will happen right after I finish disk cache. For now it's a good time for testing code from SVN.
Stay with us :)