In my experience modern DSL (like AT&T Uverse) is fiber-to-the-curb and DSL from there. Meaning the amount of DSL line you have is incredibly short and then it hits a fiber line.
Verizon rips out the copper network interface from your home and replaces it with Fios gear all the way through, which always felt like overkill though I know they do it partly to suck you in to their TV offerings too. I wonder how much the extra expense of this last 100 feet of the deployment (from telephone pole to house) holds back more broadband penetration.