Agreed. That's exactly how my Audreys are set up; I keep PhJuke and its support apps on a Linux box along with my music files and NFS mount the filesystem onto the (embarrassingly large number of) Audreys around the house.
It would be entirely possible to make PhJuke support streaming media, but it'll probably never be a well-suited app for Web browser integration. My design goal was to have it be the only thing running on the Audrey in my living room, sitting on top of an amplifier and acting like a stereo component.
Its UI will probably always be geared toward using the Audrey as a dedicated touchscreen jukebox. Though of course it's open source, so by all means everyone with a different opinion should have at it!