Aaron has put together a worthwhile post for WordPress users wanting to upgrade to WP 2.1. It’s called 10 Things You should Know About WordPress 2.1 which outlines some of the new stuff that it has including auto-saving drafts, new image upload handling, new visual editor interface and merging of links and categories.
I’ve had a play with WP 2.1 and as a WP user I enjoyed it a lot. More functional but very familiar and easy to get used to.