before you start looking for another provider remember that AT&T was recently just bought by SBC which decided to keep the AT&T name. i wouldnt ditch your DSL just because the name might change. whats going on now is no different then if SBC decided to purchase BellSouth, just a different name.
wait to see what actually goes on with this buyout and once something is written in stone i'm sure either BellSouth or AT&T will inform their customers of any changes in policy or pricing at which time then you can start running for the hills screaming
