Now that the industry has settled on a spec for 5G, carriers are racing to use it -- and AT&T hopes to be one of the first. It just unveiled plans to launch spec-based mobile 5G (not the fixed-in-place kind) to everyday consumers in 12 cities by late 2018. It's not specific about where those markets are or which devices will be the first to adopt the faster speeds, but the arrival of the 5G spec has kicked off the start of hardware development.
No, AT&T isn't giving up on its not-really-5G wireless service. The provider currently has "5G Evolution" in 23 urban areas, and expects to bring it to "hundreds" of additional markets (not to mention additional devices) throughout 2018. Like it or not, there will probably a repeat of the confusion you saw when networks tried to market fast 3G as 4G, with the real 5G coexisting alongside souped up 4G for a while.
The carrier isn't going to have a lot of lead time over its rivals. Sprint has committed to a 5G network in 2019, while T-Mobile's is due in 2020. As for Verizon? It's been testing 5G home broadband ahead of a 2018 debut, so we'd expect mobile 5G not too long after that. Still, it's an important step toward an honest-to-goodness wireless upgrade, and it could make all the difference for streaming 4K video, online VR and other technologies that absolutely depend on 5G's massive bandwidth and low lag.