Browsing the organization directory, besides just helping you to narrow down your search and find the news that interest you, allows you to create a filtering option for a customized feed.
After clicking on a category, you will find an "RSS feed" link in the results page: the URL of that feed will always expose updated results for that category.
For better customizing your feed of events, try "Filter events" in the left menu.

The number in brackets indicates the total number of events in the category, both past and upcoming