5G networks are on the way, but they won't be here until at least 2020. It seems that AT&T has jumped the gun by a few years though. They announced plans this week to begin rolling out what they are calling "5G Evolution" to about 2 dozen metro areas by the end of the year. Faster speeds and newer networks are always good, but the only problem is that AT&T's 5G Evolution network isn't actually 5G. Evolution is the key word here since this is just a stepping stone towards future real 5G deployments.
What AT&T has actually done is just re-brand their existing 4G network with some minor optimizations and called it 5G Evolution. The roll-out will also only start in certain neighborhoods of Austin, Texas and only with Samsung Galaxy S8 devices. If you are anywhere else in the country or have any other phone, this announcement will mean nothing to you.
So they are calling it 5G Evolution; what does that mean? It's still AT&T's normal 4G network but with some improvements to squeeze out even more performance. Features like carrier aggregation, 4X4 MIMO, and 256 QAM can all result in faster speeds, but it's no where near the speeds that real 5G will bring. AT&T claims up to two times the performance but then goes on to warn of "cautionary language" and that "actual results may differ materially" so your mileage may vary.
Samsung Galaxy S8 phones in certain neighborhoods will definitely see an improvement in the coming months, but calling it 5G is a stretch. It's a bit like changing your desktop background and adding more RAM to Windows XP and then calling it Windows 10 Evolution.