The general trend toward wide screens is a good thing. The first wide monitors were introduced by SGI a long time ago but because of sky-high prices, did not get to be enjoyed by the masses. Apple was the first to introduce wide notebooks with its 15.2" PowerBook Titaniums. Starting a couple of years back, LCD TVs started to hit the stores and anything above 26" were wide. LCD monitors are coming back and starting from 17" you can easily find wide versions. But there is a caveat. Not all wide is good.
A trivial backgrounder: There are three varieties of wide in terms of aspect ratio: 15:9, 16:9 and 16:10. Usually, 16:9 is reserved for TVs where HD content uses a 16:9 aspect ratio. 15:9 used to reign as the kind of wide but with advances in driver IC technology, the number of rows increased from 768 to 800, making the transition from 15:9 (1280 x 768) to 16:10 (1280 x 800, for example).
I believe there is a minimum pixel format that provides productivity enhancements when it comes to wide. What is the minimum? 1920 x 1200 (16:10). Any pixel format lower than that will provide you with a less-than-optimum experience with wide screens. One of the best ways to enhance productivity is to have two full-sized portrait windows side-by-side. By having an information source in one window and another window for information creation, productivity is enhanced quite a bit as you do not need to be constantly switching back and forth windows by pushing Alt-Tab. You simply open two windows (e.g. a browser window, a Word window), go to the Taskbar in Windows XP, right click and choose Tile Windows Vertically.
1680 x 1050 is one step down from 1920 x 1200 and most 20" wide LCD monitors have this pixel format. The problem with this pixel format is that you only get roughly 80% of a full portrait screen with a pixel format of 840 x 1050 each. Since most applications make use of a 1024 x 768 format at a minimum, horizontal pixels must reach somewhere close to 1024 pixels. Most of the time you will need to scroll left and right to see all of the page content. With a 1920 x 1200 pixel format you are looking at two 960 x 1200 portrait pages. Although not quite 1024 pixels, 960 pixels get you to about 94% of the page contents and most of the time horizontal scrolling is not required. Of course the best pixel format to have is 2048 x 1280 (16:10) that gives you two 1024 x 1280 portrait pages. I have not seen a 2048 x 1280 pixel format wide monitor yet. My guess is that Apple will come out with a 26" or 27" LCD monitor with this pixel format. Just a guess, so don't sue me Apple. Since Apple has a 23" with 1920 x 1200 and a 30" with 2560 x 1600, a 26"/27" 2048 x 1280 might fit right in, in the middle.
If DVD viewing is important to you, do not get a very high pixel format display since scaling on notebook PCs or LCD monitors are not very good. I would recommend a 854 x 480 (16:9) pixel format that minimizes the need for much scaling, but unfortunately, no notebook or monitor has this. The next best thing to go for is a 1280 x 800 (16:10) display, which is a plenty.