Google has released Google Earth 4.3 beta version, you can download it from here. According to Google LatLong blog this version gives users a higher quality 3D model of the world.
The new features includes a new navigation for richer experience when browsing mountains and buildings. More faster 3D buildings, Street view with photo overlays and more.
You can see the video to get an idea of what this version has to offer. Via Google Blog
