We're looking into the possibility of setting up a planet-style feed aggregator for Wikimedia blogs. It would be nice to get some software recommendations. Specifically, we would need an aggregator that supports - web based administration - filtering feeds based on tags assigned to posts
It should scale well a large number of blogs & readers. It would also be nice to be able to form "groups" of blogs, but that is optional.
Any tips & reviews would be appreciated.