I was just researching this very question myself, and I see no indication in any of the Samsung literature that it supports HDMI lipsync. But this may not be a bad thing. There is a detailed article online about HDMI lipsync at the DigitalHomeDesignLine.com site (google HDMI lipsync) that describes how the HDMI handshake lets the HDTV communicate a fixed delay for the device back to the receiver. But some of the delay is variable, dealing with video compression, and some of the delay occurs upstream in the video source, be it cable or even DVD. So apparently the manual audio delay adjustment available in many of the AV receivers is the best current solution. In some cases, HDMI lipsync delay can even make things worse. The article also provides information from studies that humans react strongly to the audio being early, but we accept a small delay in the audio. So the adjustment in the receiver does not need to be perfect, just enough to get the audio not to precede the video.