Steve,
Let me try to rephrase it. With MC 11, you can define a harddisk location to be your portable device. (Plugins dialog). I assume that with very little change in that code, you could allow that network folders (or any folder), to act as a portable device. There are two things you can do with that:
1) You can treat your laptop as a portable mp3 device. You maybe storing a lot of music in your main server computer, when you connect your laptop to your home network, you can easily transfer some files to the laptop, and listen music from the laptop. If your spare laptop space is larger than your music collection, this may not be useful but for many people this may not be the case.
2) You can keep a syncronized backup of your music library somewhere else in your harddisk.
My point is, I think that both of these cool features may be achieved with very little change in MC 11.