It's not like I can just pick and choose what to port.
VB doesn't interface well with other languages. Originally I was just going to port the engine over and keep the GUI interface in VB, but then I got wolfhound, and he's managed to put together a rather good GUI (still in progress) in a cross-platform library.
So by moving everything from VB to a cross platform library and language, I can make it:
1. Faster (initial estimates have 60-70% speed increase ;))
2. A Mac and Linux version!
3. More detailed graphics (OpenGL kicks butt ;))
To name a few...