In this post on my blog I describe how to add VLC Media Player to the list of Default Programs, and I supply a downloadable registry-fix for doing this quickly and easily: Adding VLC to the list of Default Programs
Do this at your own responsibility, though. And BTW, VLC must be installed in the default location of "C:\Program Files\VideoLAN\VLC\vlc.exe" for my fix to work.
Though a little late for threadstarter, I hope that my fix can be of help to someone out there
BTW, if you want to add other programs to the Default Programs list, please have a look here for hints: Default Programs in Windows 7 – adding program to list of programs