Check out the latest desktops and notebooks and you'll find a large number of them are widescreen devices. From a consumer angle, widescreen makes the machines compatible with movie watching.

From a business perspective, it's kind of a two way street; the lack of height means that you can generally see less of your document on screen (although it can be useful with spreadsheets), but with a wider aspect you can have two documents side by side and refer between them.

Years ago, the A4 monitor (including those that pivoted between portrait and landscape) were all the rage, and I used on both at home and at work. Better still was the A3 monitor (basically a 21inch); at the time I worked in an ad agency were the graphic people had an A3 monitor, the copywriters had either an A4 or an A3 monitor, and some of us were lucky enough to get a combination of the two (the owner being the only one for some to have two color A3 monitors, an expensive and extravagant option at the time).