Same issue here, my t61p that I bought in dec has horrible LCD quality. At the beginning I just took it, not having a new other screen to compare. At the beginning there was a horizontal gradient in backlighting strength. Later there also came that the left and right side were not well lit. I guess the cold cathode lamp, just as the ones on the ceiling, wear out on the ends.
Then I ordered another t61p for my brother in march, and its LCD seems to be good. much brighter overall (set at the same brightness level) and also much more even. At that point I noticed that my old one was really terrible.
What I also noticed, mine is a Samsung disply, while my brother's is a LG. It seems there is a huge difference, probably worth canceling the order and reordering if it can be seen from the order, checking the FRUs, which display you will get.
T
t61p 2.4ghz c2d, 4gb ram, 100gb 7200 rpm hd, 256mb fx 570m, 3945abg intel, wuxga, suse64 10.3