All the big manufacturers do quote 60 000 hours in their brochures, to half brightness. That's a long time, about 6 years of 24/7 time? I can't believe it will ever be an issue, something else will go pop if you turn on your screen and emigrate!
I had another thought, I wondered how much this would cost in electricity, for those paranoid about costs. At current costs, that will be £1072 on the electricity bill, to leave it on for 6 years. In normal use, say, 5 hours per day?? it would be £3 per month. Something else to take into account in your costing of screen life.