Yes, it does work great on most pages that you view. That's because web designers spend a lot of time writing many different versions of pages to ensure that they'll work on a whole range of older browsers.
New web standards with alphabet-soup names like CSS and DOM and XML have some great features that will make it easier to build and update websites. They will also allow web designers to make pages more interactive and fun. The problem is that it's hard for us to put in those features and still have web pages look good in the older browsers. They don't display the new material correctly, if at all. In short, it's very difficult to move into the future if we have to have one foot anchored in the past.
Once you upgrade to a browser that complies with the standards, you get to enjoy the new features. (For one thing, the navigation bar at the top of this page will look a lot nicer.) It's a virtuous circle, too. As more people upgrade to the standards-compliant browsers, there's less reason for designers to have to design for old browsers, which means they have more time to make pages with the new features, which prompts more people to upgrade, and so on.
Oh, my goodness, no. This website has close to 2500 pages in total, and it's a massive job to convert them all, even with some of the automated tools that are available. It wouldn't be a straight conversion, either, as I want to add some of those new features as I rewrite and improve the navigation of the site as a whole.
However, all the new pages that I write will be standards-compliant so that they will be able to use the latest technologies.
The Web Standards Project's Web browser upgrade initiative page has more information on the subject.
That's quite all right; as the old saying goes, “Everyone loves progress, but it's tough to make changes.” At least you know that the possibility is there, and you are, of course, welcome to join us in the next generation of web pages at any time.
If you have any comments about browser upgrades (either for or against), I'd love to hear them. Please send me your feedback.