Microsoft really likes what the Mozllia Foundation is doing. First it releases XAML to compete with XUL, now it looks like it’s taking on XPInstall with its open-source (!) WiX. Combined with its support of InfoPath over XForms, it seems Microsoft is trying, again, to create a new de facto standard at the expense of those already in existence.
Meanwhile, DevX demonstrates XUL in tutorial illustrating how it could replace dHTML menus. For Web sites, the method should be avoided, but for Web apps it might be worth considering.
Those who do care about standards on the Web, though, should be happy to see MACCAWS has finally released an excellent white paper on how Web standards can be benefit business. (I do hope a printer-friendly version will soon be made available, though.)