I used to stream a music from my desktop to wdtv using VLC.
I would like to stream all the sound from my iPad to wdtv.
I googled about it, but I only found how to stream music from other devices to iPad.
The easiest way is to hook up an Airport Express with audio cables to your external multimedia player, or Apple TV. Then you can stream iTunes directly to either of these devices - the functionality is built-in to iOS 4 and works awesome!