When I was at NAB last spring, I talked with Gepco about a new cable they were working on that included data, digital audio and power lines in one jacket. RunONE is now a real product and is available in a variety of configurations.
The basic configuration consists of a single run of power along with two, eight or twelve lines of 110 Ohm audio. Because it's 110 Ohm, it can carry standard analog mic or line levels, digital audio or DMX (a single stringer for LEDs anyone?)
You can also get a version that includes not one but two Cat5 data cables in the same jacket. I really wish this cable was available when I built my inexpensive stage boxes a few months back. The loomed version is fine, but we still have to run power to the musician, and it would be nice to have it all in one jacket.
I'm not sure how they cracked it, but they managed to keep the 60-cycle hum completely out of the audio lines. They demonstrated with real-time analysis (I didn't get a picture, sorry!) that showed absolutely no interference of the power into the audio lines. It was pretty amazing.
UPDATE: Thanks to Jeff (in the comments), we have a YouTube video that shows how they manage "spectral sheilding." Pretty cool. The video is not great, but it's a good illustration of how it works.
Clean stagees have become a passion for me, and this is one more step in the right direction. RunONE is available now; pricing will depend on the cable configuration.