<p>Pretty much what the title says. Is there a way to add files to a vsnet project from inside Vim? I work in a group of devs, and all of our code has solutions and projects as you would expect. I would like to use Vim, and was hoping for a way to maintain those project files when I added or removed files without having to go into vsnet. </p>

The project and solution files are in xml and are hand-edittable.  (I often have to during an SVN merge.)  However, HUGE DISCLAIMER AHOY, adding stuff from scratch is a lot more dubious than an svn merge.  I get to see the lines and just move them in (or not) here or there.  To be confident that you're not destroying the proj and sln files, you would have to experiment with visual studio a little bit to make sure what has to be added.
There are more IDEs than visual studio... perhaps there's some clues in their guts.