RSS team at Microsoft has posted a link to download the PDC slides from “Windows Vista: Building RSS-enabled applications.”  presentation. In the slides they show the diagram of the RSS objects model and a few code samples of its usage in the managed code. First of all the object structure is presented as a set of interfaces (IFeed, IFeedItem etc..) which is explained by the fact that RSS platform in the Vista are built on COM and the RCW in  .NET exposes COM objects as interfaces. Second of all, because of its COM nature the code in .NET becomes not particularly a .NET friendly forcing a developer to use Class when instantiating an interface instance:

IFeeds feedMgr = new FeedsClass();

foreach (IFeed feed in feedMgr.Subscriptions.Feeds)
{                         
 Console.WriteLine(feed.Name);
 
   foreach (IFeedItem item in feed.Items)
      Console.WriteLine("\t" + item.Title);
 
 Console.WriteLine ();
}

I am not sure why the RSS team has decided use COM for that (probably to make RSS platform accessible from VC++), but it's better than nothing, right?