I'm a little biased because I work for a phone company, so here's my 2 cents for the future of DSL....
Currently, there are 2 major reasons why a customer can't get DSL, or HDSL, or a T1 at their residence or business.
1. Farther than 12/18,000 ft from phone company's central office, in cable length. (12 is usually the limit for HDSL/T1)
2. There are load coils somewhere on your line. Most companies are undergoing massive "de-loading" projects for this reason.
Problems: Many DSL equipment manufacturers are overwhelmed, making it difficult to meet demand. It costs about a half million $ to equip a central office for DSL service. Most telephone companies are hurting for DSL-trained technicians.
Future: Remote DSLAM. (Digital Subscriber Line Access Multiplexer, i think!) Normally the mux is in the C.O. A remote DSLAM is placed near the 12,000 ft mark connected via fiber to the C.O. This extends the reach of DSL another 12,000 ft. Many areas currently have "Fiber Huts". The philosophy is similar to Remote DSLAM, enabling many customers to get HDSL/T1's in otherwise unreachable areas, but they just need to get the DSLAM equipment out there. Believe me, many companies are having a hard time keeping up with T1 orders too, and they cost mucho dinero compared to DSL! All in all, the almighty dollar wins!