This sounds really awesome, but does anyone have an explanation as to why they are doing it? Building something like Google Earth Pro must take many millions of dollars, so why would a company release it for free?
The real cost, of course, is maintaining and serving all that data. I expect that Google, in offering Google Earth Pro for free, ensures that no other competition can slide into this space, and, I also expect the incremental revenue associated with the Google Earth Pro licenses probably wasn't worth the cost of not owning that market 100%.
This is going to make life for a lot of the other GIS vendors even more miserable than it already is - I can see MapInfo being annoyed by this decision. Just spitballing, but perhaps Google is looking at acquiring them (or a competitor?)
[1] http://www.quora.com/How-much-did-Google-acquire-Keyhole-(Go...
It is great for viewing and creating small datasets. Viewing larger datasets required a surprising amount of effort in terms of tiling and converting. The tools built into Google Earth were never very good and people were pointed at server products. This was completely at odds with the simple ethos of Google Earth and often lead companies to invest in expensive ESRI products that offered Google Earth support!
Google are concentrating on server products with web interfaces and GE never fit into that. It is fantastic for professional users but Google have no idea how to sell to those kind of people.
I'm not suggesting that Google Earth will ever replace MapInfo/ArcGIS - but don't underestimate how much of the "lower end" GIS market that GoogleEarth took away from them.
So could be that Google is simply moving that team onto more strategically useful projects. Personally I can't see why they kept supporting this as it isn't core business.
Perhaps they're starting to see a handful of people relying on other data sources, so they want to give people an incentive to stick with Google?