The linux port is almost complete the only things left are getting the console to work (the in game one), making the mouse cursor go away when inside the window, and packaging a release. The porting has given me a chance better abstract things. I intend to implement a system of plugin libraries so an end user could select various rendering methods other than OpenGL. Some sort of plugin architecture would make the porting a little easier but probably won't happen until after christmas.
As for the .Net maybe. I've given up on a vb6 port since I left the project that was going to use over 2 years ago. However I am planning to do it in C# instead though I had thought of a managed C++ version I would prefer to do it in C#. A Java/JOGL version was suggested and politely ignored ;).