I used to have a website that was dynamically resized. It looked absolutely silly on a hig resolution wide screen. Each of the paragraphs on the page, when max on one of those screens became a single line or maybe two that was hard to read and design-wise: ugly.

I re-created my site using standard HTML and CSS and the first two things I did to it were to force it to a fixed width and browser-centered. This is getting more popular as people expect websites to look as good as their printed counterparts. When a page is allowed to flow freely to the browser size, the design goes out the window, whether you used WYSIWYG or standard tools.

This is the same reasoning as to why people create PDF documents - aside from wide compatibility, they want people to see the document the way that it was designed, rather than however THEIR particular version of Word or whatever happened to render it.

Certainly, there are reasons why you might want dynamic sizing, but this is usually in a case where the design is relatively unimportant, like on a forum such as this one. Covoxer provided a tweak to allow for the vertical growth of pages, allowing for things to be read from a DB or whatever. I've not used the tweak myself, but it's there to be used (free).

Looking at my Analytics for my site, there have been no less than 15 different resolutions used to view it. If I want my site to have a certain look, there is no way with that many different browser resolutions to be able to maintain that look.

MSN=centered, fixed width
Bing=centered, fixed width (except for the top header)
Yahoo=centered, fixed width
xara.com=centered, fixed width (not made with Xara, btw)
Expedia=left justified, fixed width (can be done is Xara with a tweak from the tweakset)
hotels.com=left justified, fixed width

Just a few examples of some of the most popular sites on the web.

Hope that helps.