Sony had mentioned that it was working on an OLED TV during its press conference a few days ago and we finally spotted it on the CES show floor today, 1 million-to-1 contrast ratio and all. The prototype is only 27-inches, so it won't be vying for the "Biggest in Show" prize. That's not why it's important, though. OLED is a technology that doesn't require any backlighting, so power consumption goes down quite a bit. They're also supposed to be cheaper to manufacture than LCDs, but since no actual OLED TVs have hit the market yet, it might be too early to say for sure.
OLED isn't a foolproof technology, however. There are concerns with the lifetime of the LEDs (not unlike the concerns about plasma TV lifetime). It also looks like Kodak holds several key patents on the technology, which may inhibit its growth.