I would go so far to say you don't need a designer. You need someone who's passionate about multimedia applications and is working on a HCI project that relates very much with VLC. Someone who is thinking about future UIs, and things like that. (You need to give to this person, which likely is still non recognized, the biggest project recognition of his/her time).

Except for a few things (like the conversion feature, which is really hard for non-technical people), me, and those I know use it, find VLC pretty usable.