This from today's Google Earth Blog:
By FrankTaylor on Google Earth News
A new product specifically targeted for Google Earth and GIS professionals was released today called Arc2Earth. Arc2Earth is an application which allows GIS professionals using ESRI's ArcGISbeen blogging about the development of the product and shown us a number of cool screenshots of its capabilities.
products to convert their data for viewing within Google Earth. This
means serious GIS information can more easily be made available to the
many millions of Google Earth users in the world. Unique data and maps
can be overlayed onto the 3D terrain and satellite photos of Google
Earth to enhance visualizations and presentations. For some months now,
Brian Flood (one of the authors of the product) has
Now they have released the product with a new web site documenting the product and its features, screenshots, and a link to purchase two versions
standard ($99) and professional ($299). This looks like a serious
product and I'm sure the GIS folks will be publishing reviews soon.
Here's an example KMZ 
showing a simple vegetation analysis which illustrates how symbology is maintained for polygons and graphics.
Here's an interview
with the author by Stefan Geens at OgleEarth about Arc2Earth and Google
Earth's ability to handle a variety of data and geospatial formats.
By the way, there is also another product from an outfit in Russia called KMLer which has some of the same types of features for working with ESRI products.”
