Attention LazyWeb. Let's create an ISubscription interface along the lines of the IBlogExtension interface. Here's the idea:
I visit a web page. If the page supports RSS Autodiscovery my browser's 
toolbar button is enabled. I click the RSS toolbar button and it runs all the ISubscription plug-ins I have installed. The plug-ins are passed the Uri of the page and the Uri of the RSS feed.
I have some ideas how this could be implemented for IE using COM and/or .NET interfaces. But I'd also like to think of ways to enable non IE browsers and non-COM/.NET plug-ins. Comments?