I have a lot of compact flourescent bulbs in my house. Some are nearly 15 years old. What I noticed is that as the price of the CF bulbs have come down, so has their lifespan. Seems that the newer, and cheaper, bulbs burn out or their ballasts fail but the older bulbs seemed to last much longer.
I know the CF bulbs save a lot of energy, but I don't know fit they actually save any costs because the cost savings get eaten up if they have to be replaced frequently.
The LED bulbs should be MUCH BETTER than the CF bulbs, but they are cost prohibitive compared to the CF bulbs so I won't be adopting them en mass anytime soon. I'm all for saving energy, but only when it actually saves me money.