UPDATE: In what appears be the first move toward censoring discussion of the issue, Apple Support has locked the discussion thread Bought new iMac 20" Faded Screen, which began on August 7 (the day the new iMacs were first sold) Compare Prices on iMac 20" Computers. The thread had, until it was locked earlier this week, served as the major focal point for discussion of the gradient color issue that continues to trouble owners of 20" and at least some 24" 2007 iMacs.
The discussion thread had seen a recent surge in activity since it was mentioned in the article below, and since the beginning of the holiday shopping season. From August 7 to November 18, a 95 day period, the thread chalked up an impressive 15,000+ hits, an average of about 158 hits per day. However, in the time since then, November 19 to December 10, a period of only 21 days, the thread gained an additional 9000 hits, an average of about 429 hits per day.
Further exacerbating the censorship matter, new posts regarding the gradient color issue are being deleted and replaced with error messages, as seen in this example: iMac Screen Gradient - What's the next step? (we captured a screen shot of the post before it was deleted). Apple has not replied to any of the posts regarding the gradient color issue in its Intel-based iMac Display support forum, or for that matter, even acknowledged the existence of such an issue.