Sketchup is a pretty amazing product, especially since you can download the non-pro version for free.  It's utilized by millions of people to do 3D modeling with especially loyal followings in the engineering, architecture and construction industries for obvious reasons.  

SketchUp was originally created by @Last Software.  Their team got to know Google while developing the Google Earth Plugin for SketchUp, which allows crowd sourced construction and mapping of 3D buildings and non-flat earthly features.  They had been selling their product for $500 a pop, but Google decided to release a free version along with the now $495 pro version.

They ended up liking each other and Google acquired the @Last team in 2006.  But today, Google announced they were selling the SketchUp product and software team to Trimble, a silicon valley based technology company best known for their GPS hardware and software.  

SketchUp might fit nicely into Trimble's Building Information Modeling(BIM) products.  The general feeling is that SketchUp users are a little worried since they're the ones who have been contributing most to the project over the last few years as Google has put it on the back burner.  The hope is that Trimble treads lightly and allows the organic growth of the product to continue.