I've looked into this issue a bit for my work, so I can shed some light
on the topic:
Any lamp life is a "mean life" rating. It means 50% of the population will last that long. Half will not last that long and half will last longer.
The mean life rating for most CFLs is 8000 to 10,000 hours. An average bulb in your home runs about 1,000 h/yr, some much more, others much less, but 1000 is assumed as a representative average. This implies that CFLs will last 8 to 10 years. There seems to be a lot of marketing hype that focuses on these numbers.
I read a study several months ago that looked at the effect of starting frequency on lamp life. The standard rating of 8000 to 10,000 hours is based on a lamps that run 3 hours per start. The study looked at a number of homes' usage and determined that most lamps have less run time per start. The result, IIRC, was that most CFLs lives would be de-rated to 5000-6000 hours. This would suggest a calendar life of 5 to 6 years.
In my experience, this is pretty realistic. I moved into my house in 2007 and installed probably about 25 CFLs. Since then, I've probably had about 5 fail…not too bad.
Once you get beyond the marketing hype, the reality is that they last a pretty long time, and typically pay for themselves in energy savings within the first several months of their operation.