I took the plunge on Saturday last weekend, January 20, and purchased the KDL-46XBR2. After about 3 hours at my local Circuit City, haggling prices and almost getting the 52 inch, I ended up going to Best Buy on a last ditch effort.
They not only matched the haggling price, but gave me a lower 4-year service plan as well. After 3 hours at CC it took me 20 minutes and I was out the door with my new TV.
Took it home, left it in the box in my hall for a day until Sunday when I unpacked it. Wasting no time I plugged it in right there in the hall to check it out and see if I had any clouding or mura effects. It appeared not on any of the black inputs.
I prepared my and lugged it upstairs. After about 30 minutes of cleaning and cable hookup it was all set up. So far the blacks look uniform and crisp to me. I thought I noticed a slight whiff of clouding in the top left of the screen but it's only evident when a really bright scene cuts to black. I will investigate this more and post my findings here, but so far on any blank input the screen looks to be in good shape.
First picture is taken in normal lighting with camera flash. It's the Nintendo Wii's Opera web-browser.
The rest are in a completely dark room with no camera flash.
Picture Mode: Vivid
Input: Xbox 360 420p DVD