Burn-in (yes/no) - YES
(Food Network Logo, Gears of War 3 HUD)
Model Number (ex 2011 VT30) - 2012 GT50
Number of Hours - ~250
Break-in performed (yes/no + no. of hours) - No
Usage - 70% TV, 20% Movies, 10% Games
Played Gears of War 3 for about 10–15 hours total and watched a fair amount of Food Network HD, Hulu Plus, Netflix, Science Channel, History Channel, Discovery Channel, etc. --- with contrast/brightness turned down to 50% and pixel orbiter enabled. Dark spots formed where the Food Network Logo and multiplayer HUD appeared. Haven't played Gears of War 3 for nearly a month and the TV has been in use for over 200 hours, but the dark spots are still noticeable, especially in bright scenes.
The store I bought it from (Paul's TV in West Los Angeles, paulstv.com), despite believing burn-in happens so infrequently they don't warn customers about it anymore, claims this is "abuse" and "physical damage" and refuses to return or exchange the TV. Unfortunately, it seems that using this television to, of all things, watch television has caused seemingly permanent damage to the panel. (Okay, and play video games for a weekend.)
Attached are photos of the TV. The human eye can pick up the burn-in a lot better than a digital camera can. The only adjustment I made was to the white levels to bring out the blemishes my eye can plainly see. I am not even sure what the discoloration on the right side of the panel may be. It's too narrow to be a 4:3 sidebar, and I don't know of any content I've viewed with a static image that might match that space.