I'm not a TV expert, but I am a crazy gamer. I bought this TV because I was led to believe it has low input lag. Well, mine came in the mail a few weeks ago, and it's good to know that I was told true: the input lag on this TV is quite acceptable for gaming.
I play twitchy, timing-dependent games like shooters and platformers, and I can't detect any noticeable lag on my 360 or PS3. I haven't done any quantitative lag tests, though. I'm using settings similar to the CNET settings at the start of this thread.
It's also a pretty nice looking TV, much nicer than my old Samsung plasma, so I can wholeheartedly recommend it.