Photos of the two phones side-by-side (submitted by AppleInsider reader Naoman) clearly show a visible difference. Compared to the iPhone 3G, the original iPhone's display appears much cooler due to its blue tint.
Given a choice, many users are saying they prefer the original iPhone's display over the one shipping on the iPhone 3G, though oddly Apple has said that both generations of iPhones use the same exact display.
Therefore, it's unclear if Apple will be able to make changes to the new phone's display calibration through a firmware update, or if the problem is embedded in the hardware. A number of early purchasers say they are going to attempt to swap their phones in hopes of landing one with a whiter display, though it's uncertain at this time whether Apple will entertain these requests or whether it considers the yellow tinted screens to be of issue.
In the meantime, some users note that cranking up the brightness of the iPhone 3G's display makes the yellow tint somewhat less noticeable, but at the same time this produces piercingly bright images.