Use more spectrum, get higher speeds at very short distances. They showed a prototype at BBWF they claimed would provide "3.8 Gbps @ 50 meters and 2.4Gbps @70 meters." Huawei's name for the next generation, 2-8 gigabit DSL is NG-fast. They brought a unit to BBWF and put out the press release with the information below. The speed is primarily coming by using 500 MHz of spectrum. Full duplex allows using the same spectrum for both upstream and down. The high speeds require significantly advanced processing power, raising challenging heat and space issues.
Nokia/Alcatel has been demonstrating their comparable technology, XG-FAST, at even higher speeds. It's good to see Nokia getting competition. I've asked Huawei for more technical details. I'd hope to learn more about the vectoring specifications, the chips they are using for processing, and the analog components. No word on when they expect to have units for testing, much less production.
This is state of the art and beyond, so reserve your opinions until we get results from production equipment.