Kevin,
Interesting report on Sony's XBR8's. Sony's use of locally dimmable LED backlighting in the XBR8 series appears to be similar to the Dolby/SIM2 HDR "infinite contrast" prototype that was demonstrated earlier this year. Both use locally dimmable LED backlighting. See links:
http://www.avrevforum.com/showthread.php?t=1792
http://www.avrevforum.com/showthread.php?t=1981