I read Jim Groom’s blog on a semi-regular basis. At the least, I always read the headers and take a quick glance via Google Reader.
He has been working on a rather larger WordPress Multi-User (WP MU) project for a while now. I’ve messed around with MU but haven’t had a good reason to implement it yet, but have been following his efforts.
Not only is it a pretty interesting project (though you have to read a lot of posts to really get a feel for it), but this particular post has links to some of the best RSS feed plugins for WP. I use most of them myself, though I don’t have a multiple-author blog – otherwise that would be quite a nice feature.