Well we're all happy that the iPlayer from the BBC has come to PS3 in Europe but I'm less impressed about the multi-audio output.  My setup is that the sound goes from the Playstation to the Sound System via Optical Out.  

I found that if you do enable the multi-audio output then you can play music again.  

What a bummer you can't play music and use anything else anymore.  I can still play some games and select my own music... but they're dumbass PSN games that iPhone users would have got for a pound or what have you...