What Dan said! Let me add the programmatic element. When SketchUp became a commercial tool, funding the OpenStudio plug-in became problematic for DOE. Although we want to develop software that is used by commercial products, we cannot develop software that is targeted towards specific commercial products in a given category, while not doing so for others. Why should we fund the development of a plug-in for SketchUp and not for Rhino? Or why for SketchUp and Rhino and not for Revit? Or why ...

Given that the basic workflow needs a geometry editor and viewer, we are exploring a number of free and preferably open-source options as described in the linked post. These will not be "full-featured" options and probably not even as "feature-rich" as the current SketchUp plug-in. But they will hopefully serve our purposes.

At the same time, we would be very happy if others assume the mantle/burden/opportunity of developing plug-ins for commercial products, either free or themselves commercial. If you want to develop a killer OpenStudio plug-in for SketchUp/Rhino/MSPaint and either sell it for coin or give it away for quan (karma), that would be fantastic. That is what the OpenStudio SDK is designed to enable.

We have been addressing this question on this post. Basically, OpenStudio is not moving from SketchUp to something else. Rather we are trying to support multiple options so people have more choices depending on their preferences. Some of the other options are outlined in the post I linked above.