The devil is most certainly in the details of what AT&T wants from you. I have Comcast internet currently, but would switch back to AT&T if the details of this service are favorable to me. PS Vue is going to kill my 1TB bandwidth cap that Comcast has now imposed.
I'm wondering, at least for the ATV service, if they aren't thinking, rather than an actual DVR, they offer TV Anywhere access for nearly all of their channels, plus the On Demand offerings of their own, and tie that into the "TV" app that Apple is going to send down? Then you are in the Apple ecosystem for almost everything, since you can then "favorite" programs, have the newest episodes appear in the TV app, and other available programming appear there. I would be very interested to see how this may work, and would love to use just my Apple TV, rather than Amazon Fire or Roku devices in addition. Truly ties all my content into a single device.
The only thing missing, then, is the ability to have different profiles within the TV app for others in your iCloud family, so that my wife and kids have their own "favorites" on a single Apple TV device.