I can't speak to the music-searching issues, as I haven't even bothered with that yet. I did read something interesting about streaming, however. You certainly can stream from the Zune Marketplace via wi-fi (without having to have the software loaded on another pc, etc.) But someone also found something interesting in the Zune software registry about a feature that's not enabled yet...Internet Radio streaming:http://forums.zune.net/521136/ShowPost.aspx
Check out the screenshots, too.
Now, streaming in the Zune software itself is no big deal...who cares? There's plenty of ways to stream with software. But the idea is to be able to sync your settings with the Zune HD to get wi-fi streaming on the device, itself. Obviously it's something they've at least been exploring, considering the registry hack.