The multi user version of WordPress, called WordPress MU, is finally available in version 2.8.1. You can download it from the official site, as always. This is the first WordPress MU release in the 2.8 branch, which might be a bit confusing but the version numbering is tied to the single user version of WordPress, so you’ll just have to live with it. For changes, refer to the WordPress MU trac in general, and the timeline in particular.
Thord Daniel Hedengren is a designer, writer, and blogger, and also the former editor of The Blog Herald. He used to be a hotshot in the gaming industry in Sweden, but sold everything and went International. Most recently he wrote a book called Smashing WordPress: Beyond the Blog, and does loads of kickass design.