I've done this before on a large scale (vb=>c#). You don't lose revision control history, thats still in the history for the previous file. If you're doing thin

I've done this before on a large scale (vb=>c#). You don't lose revision control history, thats still in the history for the previous file. If you're doing things in vb that can't be done in c# (there are a few things), you're writing bad code. The risk is greater in using bad technology / having legacy code.