+1 for Both will be successes in their own way. Google = Consumer Market and Esri = Enterprise. Over simplification obviously but both will likely succeed in their own way. Google may pull some Esri customers, Esri customers will participate in both, ArcGIS Online will attract new business to Esri, and others will find Google current lack of basic analysis capabilities too limiting. Luckily for those us the industry is growing so this is not a zero sum game.
Maybe, but on the other hand, Google has the ability to reach the mass public (e.g. search, Android) that Esri may never get. So I don't know...
Remember all those satelite imagery licenses that Google has? Well, all of that imagery/data is available to Google Earth Builder users. As for the pro vs. consumer argument . . . markets have always opened up as the "pro" tools (video editing, Photo editing, web publishing, etc) become increasing available to the consumer. While Esri does a great job of massaging it's loyal cult members - excuse me, I mean loyal users - the GIS market is significantly larger (10X? 100X? 1000X?) than Esri's buggy and way too technical software.
navagis.com
Re: Esri ArcGIS Online vs Google Earth Builder?
ArcGIS Online has a database that Google Earth Builder can't touch. Not to mention its capabilities when used in tandem with other free Esri software.