well it depends on the quality. You can totally dim down the brightness of the monitor, so don't worry about that.
with CRT's, you can really squeek out a few years over its life, just the image quality goes down. With LCD's, there are so many more things that can go wrong. This LCD looks VERY nice, and i don't think anything bad will happen to it really. If it does, viewsonic has great service.
But theoretically, a simple fact like the factory settings for the LCD are very bright, will not effect the life of it. Just make sure to turn it down a little, because LCD's always come really bright when you get them.
LCD's usually do have a shorter life than CRT's, but not by much. The main difference, which was touched on above, is that with CRT's, it gets fuzzy and harder to read when it dies, where as LCD's just turn off completelly
now im REALLY going to bed... its 11:30 my time.... on a tuesday, bad for school :\ (got a C+ in chemistry