Update January 19, 2012: See the latest test results here.
After a year in the lifespans of five 2011 plasma TVs that I've subjected to new long-term tests, all have shown some fluctuation in black level, light output, and color, and in some cases those changes are significant.
A few changes have been for the better, others can be fixed in calibration, and overall none is a "deal breaker" that radically changes my initial opinions of these TVs--all of which scored an 8 (Excellent) or 9 (Outstanding) in the Performance section of the reviews.
Before you read on, know that I aged these TVs in a controlled albeit accelerated process, leaving them on for basically six days a week for up to four months, so far. The charts below encompass a bit more than a year of normal use, assuming the average daily "on" time rate of 5.2 hours. When reading the charts, keep in mind that not all of the TVs have been aged for the same amount of time. See below for more details.… Read more