It's a good game changer. It's made Comcast do spin control around the fact they were rate-shaping bitTorrent.
UVerse is mostly FTTN (
http://en.wikipedia.org/wiki/FTTP) with twisted pair down the phone line path to the home. The cable looks like mini-coax. You get a set top box, and unlike Cable, the video is IP all the way to the set top box, using MPEG-4 vs. the MPEG-2 encoding seen in dish networks.
Verizon FiOS is actual fiber to the home. UVerse is twisted pair. AT&T has serious limitations because the spec they are working with is rate-adaptive like DSL, it is SUPPOSED to be able to do FastE (100Mb/s) speeds - but only in select neighborhoods do they offer the 10Mb down Internet option. They need the bandwidth for the video. Currently, they can only do ONE Hi-Def feed into a home, and that feed cuts off all other feeds. Non Hi-Def allows 4 different set top boxes in the home.
As to how many Hi-Def channels AT&T offers vs. rivals - I do not know. I wasn't really interested in that. I keep my normal VDSL, running 1Mb up and 5Mb down, and don't have normal tv. I just download shows and watch them on my Phillips player with a USB stick. But my neighbor got U-Verse. I was interested in the technology. He had to have 3 different visits by the tech to work out RF issues, but that is atypical (or so I was told).
There is probably more to debate, like how good does Hi-Def look using MPEG-4 vs. other methods, I don't have an opinion on, I haven't been privileged enough to do any side-by-side comparisons using similar TVs, etc.