Microsoft's Bill Staples gave a live demo of the new features of IIS7 (Microsoft's web server platform) here at the Professional Devleoper's Conference (PDC).
According to Microsoft, IIS7 is designed to bring the best of many worlds -- the component nature of Apache, the flexibility of ASP.net, and far easier to configure.
The most exciting thing for developers, which should impact users, is the ability to easily replace modules so that administrators can customize the apparent behavior of the web server.
During his demo, Bill Staples demoed how easy it is to replace a module. His example was the infamous file list on a web server. If you've visited a site that just has a list of files, you've all seen that ugly text directory list of files. With IIS7, that module handler could be replaced. In his example, his URL pointed to a directory of .JPGs in it. The replacement module had the user experience changed to seeing a bunch of thumbnails.
One can imagine the kinds of applications module replacements could result in.