Maybe I should put a question mark at the end of the thread title, but here is my observation (edited from the Vizio E420VL, etc. thread). I think it will be of general interest to all those who've complained about lip-sync trouble.
While I've been waiting for our local Costco to get the Vizio E420VL, I've been watching a tiny little 13" Toshiba CRT TV for information viewing, etc.
The lip-sync problem still exists on some programming with that little Toshiba CRT. So it HAS to be coming either from the Comcast DVR box or from the source itself. Can't blame the Blu-Ray player which is temporarily unhooked. Can't blame the TV, which isn't even HD.
This means that manufacturers such as Sony and Samsung are, in a sense, passing the buck on this issue legitimately. IOW, how can the video processing of a 13" CRT be slower than the audio? Yet this idea---i.e., that HD video takes a few milliseconds longer to process than the audio---is offered as the cause of lip-sync error. Now, perhaps this is still true, but it's not the TV that's doing it!
What to do for those of us without a high-end AVR with lip-sync adjustment, and who use an ordinary stereo system or the TVs own loudspeakers? It appears that Vizio is the only choice until other manufacturers start giving us a lip-sync adjustment in the user menu. (Is it a patented Vizio thing that can't be used by others?)
The various threads lamenting this problem ought to realize that the TV isn't to blame.
But does it matter? Without an adjustment, the problem is still there, whatever the source. I've seen the lip-sync problem on several HD TVs with both broadcasts and DVDs. This is now an even bigger mystery if one can't blame a TV's video processing lag.