In 2013, there have been many tweaks to usability and appearance of the basic tools in SketchUp, as well as a new Extension Warehouse, a place for extensions and plugins that extend SketchUp's basic features.
SketchUp Make is free, while SketchUp Pro is $900. The Pro version adds a 2d drawing package, LayOut, and some 3d export features. SketchUp Make is sufficient for most Scout pioneering purposes. You can read more about the new release here, and download SketchUp models from Ropes and Poles here. I wrote a set of tutorials for building pioneering models in SketchUp that can be read in the blog archives.