I agree. Air Video has been the best purchase I made from the App Store. I can stream my entire library in incredible quality on the IPAD. I ended up with Air Video because Zumocast is not available at the moment.
I wrote Air Video and asked when they were going to support MP3 streaming in their application. They said they were thinking about it, but now it doesn't matter. They referred me to AudioGalaxy. It's free and works perfectly. I can stream to my IPAD or IPHONE to any Music Library on my home network.
It has absolutely nothing to do with Itunes (That's a good thing). For those who are trying to figure out how to stream their shared itunes libraries to their IPAD, check out AudioGalaxy.com. There is a server piece and a free app for the Iphone and IPAD. The other day, I went to the gym and got on their wifi with the iphone. I streamed my choice of music from my home server - this app works flawlessly and it's FREE.