As someone who works professionally (gaffer, film industry) with all different forms of lighting,( led, tungsten incadescent, hmi, flourencent, carbon arc, hell i even got the philips prototype oled luminblades) let me say this, they all suck but for different reasons.
Led have plenty of suck ... First led droop, ( which last time i looked no one had really figured out) the lost of effeciency as power levels increase mean there's a serious limit on how brite a single source led can be so you are required to stack them, basically stick a bunch together to make the whole brighter this causes tons of issues not only optically, rather than having a basic single source which you can then optically focus you are limited to a multisource array with muliple shadows, rainbowing, and plenty of other artifacts. This also it a major heat issue, while a single led is much more efficent than a incandescent per watt it is also much much smaller so has less surface area to disperse heat. When you start stacking dozens of them closely together this becomes a major problem. I always find it amusing how shocked people are when they see the massive heat sinks on the back of large professional led arrays.
There are even household bulb designs that are using liquid silicon to help deal with this issue.
When you combine this with the circuitry required to run them and the fact that most arrays are built as a single unit, so when you lose indivisual leds you can't replace them and eventually need to replace the entire unit, so while a 50,000 average hour bulb life sounds great when you realise what your really saying is a 50,000 average unit life not so good. I have units on my truck that i use almost daily that are almost as old as i am, i can be pretty certain that none of the led units i have will be functional a decade from now.
Then there is colour, and from reading the above comments almost everyone here need to brush up on their colour theory, lets just say like all non black body emiters leds are a nightmare when it comes to colour. Yes there is no such colour as white but the one thing white is is full spectrum. Led, fluorescents, hmi and other non fullspectrum all have had allot of effort and investment in getting arround the fact that they are naturally missing chunks of the spectrum and most are able to get thier cri (colour rendering index) up to the low 90 in optimum conditions, the thing is optimum conditions don't tend to stay optimum, and when you have a bunch of mixed sources and they all start going off optimum in thier own way on set, well, this is why gaffers tend to nervous wrecks.
Yes led can as a side benifit of having to be stacked have the option of rgb mixing, or for the better arrays rgbcow, but while this may work well as a wash across the back wall the human eye is very atuned to skin tone, especially green and red as its important evolutionarily i suppose to know when a fellow tribe member is about to attack or puke on you, and the limited bandwidth options with the indivusual elements of an rgbled has meant allot of overselling of the usefullness of this option.
Lets not even talk about the nightmares that can happen when dealing with frequency, most led dim by changing freq of on/off cycle rather than brightness which when mixed with the fixed freq. of camera, or the eye of a person who has trained himself to notice freq, can produce incrediblely anoying artifacts.
So yes, .. Led is an useful option, but does not in anyway replace the need and function of incadescent glowing tungsten wires of the basic classic bulb, not in quality or high output, and while led will always have function where it makes the most sense, and we have seen allot of improvements lately as the tech has matured, as we have recently with the more mature fluorescent - the new t5 and t4s are very impressive, it is not the best option in all situations and i actually am very willing to bet that it will not be the unit thats lighting your homes twenty years from now.
Now ... Radio activated plasma bulbs ... That I'm excited about.