The Kinect hardware is not built into the TV at all. It does not require any special TV—any old TV (even an analog CRT) will work just fine. Kinect requires an Xbox 360 console to function. Kinect is connected to the Xbox 360 by USB, which connects to the TV by some type of A/V cables.
The Kinect sensor itself consists an array of cameras and microphones. These devices send their input data (video & audio) to the Xbox 360, which processes that data in software. Using that data, it creates a 3D model of the users' skeletons, and then it uses how those skeletons are moving to control the software. It also uses voice commands to control the software.
You can buy the Xbox 360 and Kinect together as one bundle, or you can buy them separately. Kinect only works with the Xbox 360; it does not work with PCs or any other type of console. It is probable that hackers will reverse engineer it and figure out how to get it to work with the PC in the future, but keep in mind that if that happens it will almost certainly be illegal and not licensed by Microsoft.