I wrote before about Humanitarian News, which imports the latest updates from 600+ news sites and blogs.
Humanitarian News already featured an extensive set of RSS feeds, split up per section, but now you can generate your own RSS feed customized with the subjects YOU are interested in.
You simply execute any search, and click on the "XML" icon to generate a feed out of it. Check out the subscriptions page for more details.
I use it quite extensively at work, to check the latest updates of certain events or subjects I am following. As Humanitarian News keeps track of more news sources than any other site, and all sources are hand picked, the searches go deeper and are more relevant than what e.g. Google News Search would offer you.