LED backlighting is no gimmick, and I say this as a man who openly dislikes the LED edge-lit sets Samsung is peddling. By all objective measures (I have taken such measures myself), except for viewing angles an LED backlight provides a superior image. Also, only the LED edge-lit LCDs have the slim form factor. The full LED backlit locally dimmed sets are still plenty thick.
The 8500 is Samsung's new flagship locally dimmed, full LED backlit LCD tv, intended to replace the famous A950. It is not in stores yet. BB has it in their system, but not in any stores, to my knowledge. They should be in BB/Mag. stores in about a week and, given BB's special relationship w/Samsung, in other retailers' stores in 3-6 weeks. They are expected to be very strong performers. As soon as they hit regular retail stores, I will be testing and reviewing one, probably in the company of a very accomplished professional calibrator (eddiscus). For the cyber-location of my review, see my sig. file.
Yours,
David