Google adds instant translation to Google Reader
Or you could use a service like Mloovi to translate the RSS feed, but Mloovi has a few limitations, like the inability to show pictures or full feeds. Now it looks like Google is taking things into its own hands, by combining Google Reader with Google Translate.
Here's how it works. Just subscribe to a blog or news site in another language (assuming you can find the subscribe button). Then go to the feed settings in Google Reader and select "Translate into my language." That's it. You only have to do this once per feed and Google Reader will automatically translate that page until you tell it to stop.
Keep in mind, these are machine-generated translations, so they're far from perfect. But if you don't have time to learn French just to read a few articles from Le Monde from time to time, this could be the next best thing. Or maybe the thing after that.