Here's a picture of my MPOE/demarc. This house was built in the 1940s, but this demarc is more modern. It might look like a mess, but \some of the cabling still looks solid. I've had ADSL from PacBell or AT&T since around 2002, and this copper has been good enough to serve those low speeds.
I'm thinking about replacing some of this old wiring, in part because I need a better demarcation point where I can isolate internal vs. external wiring problems. I'm not sure who 'owns' the Demarc.
(The following is an image on Picasaweb, which may or may not work with BBCode):