You guys may or may not be interested in taking a look at my efforts in importing/rendering Collada models in a C++/OpenGL environment on my game development blog:
http://tomeglenn.tumblr.com/tagged/Aries_Engine
My engine is no longer under development, however, I am willing to release the source code for my Collada importer/renderer if you think it will aid in adding 3D characters to Visionaire.
I should note that I developed this in C++ and OpenGL on Mac OS X. However, I have not used any native code, so this should compile on any platform. It also makes use of the RapidXML C++ library.
It's also worth mentioning that this code is by no means complete. It can simply load Collada models and display them. It doesn't load lighting/animation information.
Most engine builders seem to focus on using 3D Studio Max which is usually beyond the average hobbists pocket or Blender with a massive learning curve
I know its been ask before but a panoramic option would be nice, ie a way to use cube faces or spherical images.
Flash support would be cool with the ability to make Visionaire respond to commands from timeline