I'm a light bulb geek. I don't know it all, or even a lot, but I admire lighting and new lighting technology. With lighting efficiency it's all about Lumens per watt. 60 years ago, we still had big sporting events, stadiums, what-not, but then they were using huge incandescent or arc type lamps. If you are going to use the light anyway...stadium or in your bathroom, why not go with more efficient? From a personal standpoint, it saves on your electrical bill, and they last longer...they do last longer(fluorescent, CFL's, HID's)From an Engineers' standpoint, they save money...smaller wire size, less annual maintenance, more fixtures per circuit and lower cooling costs....and they cost less to run. From a tree huggers standpoint, the help save energy...even when it is used somewhere else, they rejoice that a ferret bat is saved. From a utility's standpoint, they don't have to make upgrades or expansions as soon as they thought...that's why they offer those rebates.
Lighting is huge....most probably don't think about it, but there is a lot of lighting in this country/world. Replacing incandescent with CFL's in my house cuts my lighting load almost 80%. Sure, here in Minnesota they take a while to warm up in the garage, but I can live with it, and I know some people won't, but that will change...people used to be okay with changing incandescent's every 6 months (I'm sure that is inaccurate, but I have not changed a CFL in 3 years.)
Price wise, an incandescent bulb is somewhere between 50 cents and a dollar, CFL's cost $6.00 for a 4-pack, and I'm pretty sure the people that make them are not selling them for a loss.
LED's will follow eventually...CFL's used to be expensive as well...when more people make them and more people buy them, the cost will come down. Single LED components used to be expensive, especially blue and white LED's. I suspect the cost curve for LED's will drop faster than the cost curve that CFL's took, because there is much more consumer interest now in LED's then there was for CFL's 15 years ago.
Take a quote from Wikipedia for what it's worth, but it's mentioned there that LED light output actually rises at colder temperatures.