It is already happening; there is a virtual island in Second Life where Jeff Corbin of the University of Denver feeds data from hundreds of weather stations to reconstruct the real weather over a map of the US- your avatar can walk inside a weather map. Second Life is getting more real all the time.
Meanwhile, back on Google Earth,
In this image the author inspects a live weather map built for the National Oceanic and Atmospheric Administration in Second Life.
there is an "explosion of user created content such as travel photos and blog posts pinned to specific locations". Di-Ann Eisnor of mapping site Platial says "I can imagine a time when the base map is just a frame of reference, and there is much more emphasis on the reviews, opinions, photos, and everything else that fits on top."
Additionally, more real world data are being added to Google Earth; weather conditions, webcams, even "nest-cams" of birds nests in nature reserves.
"Google Earth itself is really neat," comments Jamais Cascio, co-founder of Worldchanging. "But Google Earth coupled with millions of sensors around the world, offering you real-time visuals, real-time atmospheric data, and so on--that's transformative."
It hasn't happened yet; you can't bring a Second Life avatar directly into Google Earth. But it is coming and the implications will be huge.
"What I want to do one day is represent the Grand Canyon or a national park with such fidelity that you could essentially go there and plan your whole trip," says Michael Wilson, CEO of Makena Technologies, the company that operates the virtual world There. "Or what if you could model a Europe where the sea level is 10 feet higher than it is today, or walk around the Alaskan north and see the glaciers and the Bering Strait the way they were 10 years ago? Then perceptions around global warming might change."
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With Google Earth, it is now possible to zoom inside Berlin's Reichstag building, as shown in this image and the next few.