John Bristowe and Jeff Julian have built an ESF extension for NewsGator. With this extension installed, if a feed publishes information about an event in a certain way, a new item will get added to Outlook's calendar with the event details.
John has a sample feed and a screenshot in Outlook on his weblog...check it out. This is really beginning to demonstrate the power of RSS extensions, when used with an extension-aware client. Nice job, guys!