Two Different Screen Issues Being Seen by iPad 2 Users
There are two issues, both related to the screen. The first one is reminiscent of a similar one when the iPhone 4 was launched. Some users have observed a faint yellow tinge to the screen in some areas.
With the iPhone 4, it was eventually explained as a bonding agent used in the construction of the iPhone 4. It's likely this is the same issue as in that case and will go away once the agent has time to set.
The second issue relates to a small amount of light bleeding onto the screen from the edge of the iPad 2 when watching a dark scene in a video or using an app with a black background. It can be handled by adjusting the screen's brightness, if necessary.
It's not uncommon in LCDs of all sorts for this sort of bleeding to occur. It's also true that people want their products to be "perfect," especially iDevices.
You can watch a video of the screen bleeding issue below.