All in all I don't see LEDs becoming spherical in design anytime soon as I don't think that they will every get to 100% efficient there will always be considerable heat to deal with such that the emitters will have to be "connected" to metal heat sinks.
What would be optimal though would be a tiny LED sphere that outputs about 2000 lumens with very little heat that could be managed perhaps by a small diameter mounting metal pillar on one side. If this ever happened we could see it used in parabolic lenses and glass bulb type situations it would essentially be a direct replacement for a filament then with the exception of having electronics to manage power to the LED.
What would be optimal though would be a tiny LED sphere that outputs about 2000 lumens with very little heat that could be managed perhaps by a small diameter mounting metal pillar on one side. If this ever happened we could see it used in parabolic lenses and glass bulb type situations it would essentially be a direct replacement for a filament then with the exception of having electronics to manage power to the LED.