When I first started using VLC and I found that it had no support for the media keys on a multimedia keyboard. I'm not sure if there is any plan to add that ability or not. But in the meantime, I made a little program that will allow one to use the media keys to interact with the VLC. It's freeware. (Sorry, Windows only. I just dont' use my Mac or Linux as much as I used to)
It can be found on my site here:Media Keyboard 2 Media Player
(MK2MP)
Media Keyboard 2 Media Player gives some media players multimedia keyboard ability, which previously did not have such support, such as the play/pause button, next and previous buttons on multimedia keyboards.
http://www.paraboliclogic.com/programs/mk2mp/index.html
It is still in beta, so if anyone actually uses this and finds any problems with it, please see the help file for ways to contact me with whatever problems you may find. Hopefully I've already worked out the bugs.