HDTV Video Delay
The Delay in the video signal is a result of the upscalling (or downscalling) performed by your TV. This happens in any HD set whether it is a plasma, LCD, rear projector, front projector, etc.
You might find little or no delay when you are viewing program in the native format of your TV. (i.e. HD cable in 720P). However, the amount of delay will be greater when it has to downscale a 1080i signal or upscal a 480p or 480i signal. The amount of delay will depend on the performance of the scaller in the TV.