Donncha O Caoimh have announced version 1.5 RC1 of WordPress MU, which incorporates the design from WordPress 2.5 and other things. It is said to be stable, but being a release candidate it’s not meant for production use just yet. Version 1.3.3 is the current version.
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.