You've got to remember that "at&t" (the current one) is not AT&T, the remains of The Bell System resulting from the 1983 divestiture. SBC, which started out as a Regional Bell Operating Company named "Southwestern Bell", bought the old AT&T at firesale prices back in 2005 and assumed its corporate livery. SBC and Southwestern Bell before it, never made a secret of thinking that the 1983 Bell System breakup was a mist…
Also, you forgot the part where shortly after SBC bought AT&T, the "new" AT&T bought Cingular, a partnership between Bell South and the former AT&T. Oh, and the part where before buying AT&T, SBC also bought Ameritech, the parent company of the Illinois, Indiana, Michigan, Ohio, and Wisconsin "Baby" Bells, and Pacific Telesis, the parent company of Pacbell and Nevada Bell.
...and what of the other "Baby" Bells? Well, Bell Atlantic and NYNEX combined to form a company you may have heard of: Verizon!
(source...and a fun read: http://en.wikipedia.org/wiki/Regional_Bell_Operating_Company...)