U-verse recently became available in my neighborhood so I decided I'd ditch Comcast and give it a shot. This Wikipedia article is a pretty decent summary of what the service is all about.
In the house it is based around a 2Wire 3800HGV residential gateway. Of the 25 Mbps down and 2 Mbps up of bandwidth, 10Mbps down / 1.5 Mbps up is reserved for my internet connection. I've conducted speed tests using various testers across the net including multiple NDT servers, and the results are pleasantly consistent.
The highest speed I've observed is 9.52 Mbps while downloading the ISO image of Ubuntu from Georgia Tech. My Comcast cable connection could beat that when in its "Speedboost" mode, but that only lasts for a brief period of time. My download speed from Tech did not fluctuate. I prefer having a constant, predictable speed.
The gateway can also serve as an 802.11g wireless router, but I'm not using that functionality. I just set up my 802.11n base station to operate in bridge mode and disabled the wireless on the AT&T box.
The TV service works well, too. You need a decoder box for each TV. They use the coax wiring already present in the house to communicate with the gateway. The user interface falls somewhere between the crap that is Comcast and the perfection that is TiVo; I'd say it's closer to TiVo on that spectrum.
Overall, I am satisfied. I'll post updates if my opinion changes.