Yahoo calls it Pipes, but I call it drag-and-drop mashup creation. Absolutely no programming knowledge is required to create Pipes with Yahoo's new tool.
With Pipes, you start with one or more sources of data. These can be search results from the web, from a map location, or from Flickr; or the data can be an RSS feed like from a blog or news site.
After you create your inputs, you can massage the data with Yahoo's secret sauce -- modules that you can drag in to filter, translate, and otherwise modify the incoming data.
An example of a Pipe you can create is this one where I combined the posts and comments feeds for Freshblog into one aggregate feed using the "Union" module.
In this simple example, I've taken the Freshblog feed and run it through the BabelFish module to quickly create a Spanish language version of Freshblog. You can conceivably expand the audience of your blog by providing a separate feed for each of the 12 languages Babelfish supports.
A great way to learn Pipes to to start with the simple examples above and modify them. Have fun with it!