There have been many sketchup models exported to google earth, from novice modelers to advanced professionals, they are all unique. I found this presentation to be a good example of a fly-through, produced using sketchup as the main software. I have personally used sketchup on 4 occasions, and it got the job done for its purpose. I have never done movie presentations using this software but as you can see, it is possible and it looks good in my humble opinion. What I like the most is the fact that it has that fluid look to it. Go SketchUp!