Ummm Google Earth does have 3D capability, they extract DEM's (Digital Elevation Models) from the imagery using image correlation, or in some cases acquire it seperately through other means (RADARSAT etc).
Then they drape the satellite imagery over the DEM to give you a nice 3D image.
All you have to do in Google Earth is use the free look function (Middle mouse button and move the mouse in the direction you wish) and hey presto 3D. Or you can use the elevation angle slider on the top right hand of the screen.
Here is a 3D image I screendumped over the Lauterbrunnen Valley in Switzerland. Even though the mountains are huge in real life, they are of even greater proportions as the aspect ratio (height/distance)is ramped up so you can pick up minor elevation changes in Google Earth in 3D mode.
