At this point, it doesn't matter cingular or ATT, come november it will be the same company when the papers are signed. Then there will be a 6 month aquisition period, July next year AT&T Wireless will be no more, your bill will say cingular. As for signing up right now with either is up to you. Again come July they will be the same company, same billing, same plans etc. As of now AT&T and cingular have the exact same plans, with a very few minor exceptions (such as roll-over).