I'd think the LCD panel itself will greatly outlive the backlight, the component that will die first will most always be either the backlight inverter or the backlight bulb. Inverters are easily replaced in many cases and inside of that it's usually capacitors (or "caps") that fail so that one component can be replaced to keep the monitor going. I would think that the LCD panel would last much longer than 100,000 hours, it doesn't really wear out under use and isn't put under much stress.
An LED backlit LCD should last much longer (LED's last practically forever, they don't "burn out" like other lights do, just get dimmer over time, they only burn out under excessive voltage/current).
Also, LCD TV's and PC monitors are one in the same, both consist of an LCD panel (a glass panel with liquid crystal material in it and ribbon cables to attach circuitry along the edges), some filters/polarizers that go behind or in front of the panel, and some sort of backlight (most monitors/TV's use small fluorescent tubes, bigger displays use more tubes, smaller ones use only one or two [most monitors use either one or two, TV's sometimes more]). If the backlight is fluorescent (or electroluminescent) it needs an inverter to step up the low voltage to high voltage that drives the light. This circuit is under fairly high stress compared to the rest of the monitor and is one of the first components to fail. LED backlit TV's and monitors do not have an inverter (LED's run at low voltage) and thus do not have this failure issue.