Good job, but there appears to be one feed / source that's nothing but uninteresting (mostly because they're personal responses) Twitter-type entries. @Peter starts a lot of them..
I suspect there are quite a few rules / heuristics that could be used to improve the quality of "planet" sites overall. Those in the topic areas I'm interested in tend to pick good sources, but those sources can occasionally be "noisy" and irrelevant to the planet. This leads people to subscribe more to summary blogs (to my advantage in my main niche).
It's probably rather beyond what you're hoping to achieve, but with some time and thought, I bet there's a way to build planet sites that have an incredibly high signal to noise ratio rather than the almost equal one they tend to have right now.
I think aggregations typically fall into one of a couple of category: topical, from the trenches news, or community building sites.
I'm mostly hoping that this will be a community building site, and in that case I think that some off-topicness is acceptable. I'd say that a target signal-to-noise ratio is about 80% :-)
The other 20% helps to give character to the people that are being tracked. At least for "planets" like the three I mentioned in the original post, the site is mostly for the people that are collectively posting there, and has the side effect of making it possible for fans to easily peek behind the scenes.
I should warn, however, that being included in a planet can cause some people to think a little too much about what they post. My personal blog is included in a planet and I'm often wondering whether I'll get kicked out if I post something irrelevant or cause too much noise. Really, I should be able to get that planet to subscribe to a certain /category/ on my blog so I get the choice. Just bringing this up in case it becomes a point later on..
Many blogs do allow for RSS feeds based on categories, and I know of a number of people that have their blogs aggregated based on those category feeds. If a particular feed gets too noisy that's something that we'll deal with (as I've seen done on other planets), but there that usually amounts to, "Uhm, can you set up a category feed?"
I personally just have three separate blogs -- one for a few friends, my KDE blog which is fairly widely syndicated, and now the Directed Edge one. I tend to include bits of personal information in my KDE blog from time to time, but still keep in mind that it's mostly being read by people interested in my open source work, not girls I'm dating. ;-)
