Google earth 4 is now out of Beta, complete with the recently upgraded SketchUp (6).The newest version of Google Earth 4 is 4.0.2722,which has been declared “Non-Beta”.

Google Earth has also developed a “Product comparison” page, where the user can find the most appropriate version for them, however the free version is still good enough for the majority of users.
The latest version can be downloaded on this page on Google Earth.