we use for WordPress for our community journal and because we are some development fans we enjoy updating tools with subversion and automatism. We update wordpress almost daily, sometimes more.
Since you did major improvements to the WP admin interface I really miss a neat feature:
"Continue after editing".
Before you can preview a new post, you have to save it (autosave is just _not_ enough). Currently you are redirected to the posts overview and a little box (edit | show post) occurs. Because of this behaviour some persons started new postings after saving the draft instead of continuing editing, they just thought the post is lost.