With an ADSL router and a networked environment, everyone should be able to share the same connection. You want the absolute highest downlink speed you can get if there are ten or more people who might be using the system at once for ten simultaneous downloads of large files. This is T1 speed, and many large offices do fine with it. The home environment is still where this service will shine, although the providers are all pushing DSL into small businesses, believing that cheaper cable modems and 56K will dominate the home. But when voice over DSL begins to work, it'll be possible to pump five or six or more voice lines over a DSL connection.
Many families have two to four phone lines plus a cell phone or two.
There's no reason for all this redundant copper when a single twisted pair will do the job and do it better. So they're roadblocking implementation despite legal mandates.