I think a tool that would allow you to hollow the inside of a block then let you run wires through the block would be really useful. It would help hide wires and be helpful for hooking up machines indoors.
Isn't this what Facades are for? you make a "cover" of a block, then you place the wire, then you place the cover to hide the wire.
If you really need it inside a block, I believe construction foam can cover a wire as well. I don't recall if you can place a cover over construction foam / reinforced stone, but that would be a neat future capability.
I'm not sure about a "cover" over construction foam, but there is the Obscurator:
I haven't used it much myself, since I only play single-player and prefer to have my cables visible.
I am pretty sure you can do that with a construction foam. You can fill blocks with foam while wires will stay there and preserve all conductive properties. https://wiki.industrial-craft.…p?title=Construction_Foam