preferred audio language should fallback to 1st available audio
In "Audio - Preffered audio language" settings you set something like: slo,cze,eng
Then when you watch e.g. a transport stream which has none of these audio languages available, but instead it has only ger or ned audio, vlc will not select it but plays silence instead.
So, when there's none of the preffered audio's in the stream, vlc should select whichever is available, perhaps the 1st one.
This is in vlc 1.0.0-rc4.