They didn't/couldn't count the AT&T Worldnet accounts, either dial up or DSL, in the SBC totals. SBC only reports their broadband totals. I suspect that there are at least 100 to 300K Worldnet subscribers after deducting the BYOA accounts.
Bellsouth had 3.6M DSL lines at the end of '06 according to the AT&T Q4 conference call.