Wordpress 3.0 arrives, with multi-blog support and new default theme
Wordpress 3.0 also features extremely convenient bulk updates of plug-ins and themes, so you don't have to do them one at a time. On the widget front, the coolest new feature is custom menus, so you can do your site navigation your way. Because Wordpress can occasionally be confusing, there's also help on every page now, to help you get a handle on all the new features.
There are honestly too many improvements to Wordpress to do them justice in one post, so I suggest you check out the very useful overview video below.