The FOSS Planet seems like a nice idea. It's almost too exhaustive for my needs, but I'm sure I'll be reading it anyway.
It's difficult to please everyone with this sort of thing. I recently stumbled upon Planet PHP, but it didn't interest me (despite my interest in PHP). It includes too many blogs from people that I'm not interested in and is missing too many blogs of people that I am interested in. Plus, it uses blog titles instead of people's names, which makes it difficult to distinguish the two.
FOSS Planet lists people's names and is pretty exhaustive. So, it at least solves two of those problems. At most, you only have to avoid the blogs of the people that you may not be interested in. Nice job, Steve.