Link - Mapdex in GoogleEarth 2
Mapdex is fully integrated with Google Earth. All mapservices that return a valid projection will have the ability to be added into Google Earth via network links.
Just like that, Mapdex now supports Google Earth. Jeremy was nice enough to also release the ColdFusion code to take any ArcIMS service and allow it to be viewed in Google Earth. Anyone who is currently offering up ArcIMS services should seriously think about offering Google Earth support as it is so easy to do.
Of course as always you can add these ArcIMS and WMS services to your ArcMap by following these instructions from ESRI.