From the New York Times - Green Inc.
"The chief technology officer for Lunera Lighting, an LED start-up company, warns that trying to put new, energy-efficient lighting technologies into sockets intended for incandescents is akin to putting a square peg into a round hole. When LEDs are exposed to high heat, they’re going to experience color shifts, you’re going to get reduced output from these fixtures and you’re going to get disappointingly short lifetimes."
In its first implementation (R-30 reflector bulbs), Vu1's ESL technology is being designed specifically for existing recessed can fixtures. We don't expect that 800 million recessed can fixtures will be replaced anytime soon.