From what I've heard this is supposed to be true of high performance xenon bulbs used in lights such as Surefire. I can report that in three years of heavy use of a SF 8x rechargeable, I am still using the original lamp/bulb. I have often used the light for 1 or 2 second periods, and sometimes had to use the light well past the point where it began dimming out.
On my other SF rechargeable, the lamp blew within the first minute of use. (Surefire replaced it at no charge.) It seems to me that lamp quality is much more of a determining factor in lifespan than usage.
Of course you don't know how good of a bulb you have gotten, until it blows on you. /ubbthreads/images/graemlins/eek.gif