A few minutes ago, I wrote how you can get RSS-feed based desktop slideshows in Windows 7. But if you’re interested in adding feeds of your own, you can follow the method given below.

How To Add Own RSS Feed for Desktop Slideshows

Unfortunately, there is no means to control what feeds to add and what to not. Currently, this has to be done manually only. To add your own RSS feed source, copy/paste the following text in your .theme file with the help of a text editor.

[Slideshow]
Interval=1800000
Shuffle=1
RssFeed=http://www.fabrikam.com/Feed

You will have to login/logout (user account) or toggle between two themes to force a manual refresh.