I used the planet code to set up munichblogs.com, with an initial random selection of blog feeds. Hopefully there'll be some natural selection of bloggers over time. I plan to add some subculture blogs under that – For instance, I'd like to know about any and all blogs for open source developers in Munich.
Feeds seems to be of variable content, possibly depending on the formats (planet seems to handle any feed format automatically). Some have full text, and some have just the first couple of sentences. Some have links to the images shown on the original blogs, some do not. Maybe planets are test cases for feeds.
planet makes it really easy to do this – so expect a lot more planets to appear.