They are already planning the transition. »www.att.com/shop/wireless/device ··· ver.html
now allows you to replace your wired phone service with a wireless based one and with the latest LTE devices the speeds are well above what can be attained with DSL. I have already seen prepaid plans with 50Gigs of data for $69.95. The data buckets will eventually grow for each carrier due to competitive pressures.