I heard a pretty in depth review of the TV stuff on the Giant Bombcast this week. The person reviewing it was using a Directv DVR. The general summary is that it works really well for some things and not at all for others. First it doesn't sound like there is any way to watch DVR recordings without using your remote.
Second, the Kinect voice recognition seems to have trouble with channel names. ESPN was the main example he used but he said this is also true for HBO or other families of channels that start with the same name. He said if you say "Xbox watch ESPN 2" (or ESPNU, ESPNews, ESPN Classic) the kinect stops listening after it hears ESPN. It thinks you wanted to watch the main ESPN channel no matter which words you say after that. He also couldn't get it to recognize AMC. He said it would bring up other channels like A&E and Spike TV instead. Speaking of Spike TV and other channels with "TV" in them... He said the Xbox would just think he was saying "Watch TV" instead of the channel he said. Some other channels like TVG apparently aren't recognized by the abbreviation they use in the logo and on your guide. You have to say TV Game Network instead but when you say the TV part at the beginning it confuses the Kinect. He said he was able to get it to recognize some of these problem channels by adding them to the favorite channel list. Apparently the channels in your favorites list get higher priority from the Kinect voice sensor.
One other issue is that for some reason it strips out the Dolby Digital 5.1 track from your cable/satellite box. You can choose to have it convert the DD5.1 to PCM 5.1 or DTS 5.1 but this is still in beta and apparently it doesn't work with all cable/satellite boxes. There is currently no way to just pass the DD5.1 audio through unaltered. Depending on how well the conversion works and if there is any loss of audio quality that would be enough reason for me to skip the TV integration feature. If it successfully converted my Hopper audio to PCM 5.1 with no noticeable quality loss I would probably still use it. There is no way I'm going back to stereo for all my Dish programing though.