Slimming Down the Backlight
I don't speak with any authority on this, but it would seem "easier" to produce a slim plasma than an LCD. A plasma panel is self-illuminating, but a LCD requires some sort of backlight. But JVC has developed a new slim backlight to solve that problem.
LEDs would also seem to be more space efficient than the CCFL (fluorescent) backlights still used in most LCD televisions. While there were no LED backlights in sight for JVC's current or just announced models, the company did show a design with an LED backlight in a separate, photo-free zone where some of the company's upcoming technology was on display. Expect to see this feature in future JVC designs.