You should see the back to school specials at our local Best Buy. There is an Acer desktop with a 17-inch CRT monitor, for those who can’t afford the extra 70 bucks for a 17 inch LCD.
Of course that system is the exception. Most of the computers are laptops with 15-inch displays and I think the trend is that more and more people are buying one of these and not bothering with a desktop anymore. The larger trend might actually be toward smaller displays not bigger ones.