Not a gigabit but pretty darn good. AT&T, assured the DirecTV merger is going through, is about to go public with the long-planned upgrade of ~5M U-Verse homes to hundreds of megabits. They will take four years and reach about 15% of their homes. Gigabit gear won't be available for several years.
Randall Stephenson in 2004 told Wall Street AT&T was using fiber, not copper, for all “new builds,” although I believe it took a few more years. “New builds” are 1-2% of the network each year. That suggests four million to eight million homes are ready with FTTB.
With most of the construction already done, the upgrade will easily fit in AT&T reduced capital budget. I estimate G.fast will cost $75-250 per home passed. The cost over four years is is only a few % of annual capex and will be recovered in months from customer charges. It would be stupid not to upgrade and AT&T's top management isn't stupid.
The 400-700 megabit down speed of today's G.fast is confirmed by the early field trials. I previously reported that Swisscom, "Gets between 285 and 402 Mbps downstream and between 85 and 109 Mbps upstream. Results depend on copper cable length: on short copper cables (ca 24 meters) we were even able to reach 624 Mbps Downstream / 151 Mbps Upstream in field but without connected customers." Telekom Austria measured 536 megabits down and 116 up.
The chart below, from Alcatel, shows combined upstream and downstream speeds in early testing. Combined, the speeds up to 150 meters are 500-800 megabits. Subtracting 100 megabits for the upstream yields 400-700 megabits downstream, what I had estimated from a different data set.